diff --git a/Cargo.lock b/Cargo.lock
index a19426640..7b3a3d3cc 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1250,7 +1250,7 @@ dependencies = [
 [[package]]
 name = "parity-ui-precompiled"
 version = "1.4.0"
-source = "git+https://github.com/ethcore/js-precompiled.git#5e3b9629692c550811b228d68ca99d1461a4f6cb"
+source = "git+https://github.com/ethcore/js-precompiled.git#957c5a66c33f3b06a7ae804ac5edc59c20e4535b"
 dependencies = [
  "parity-dapps-glue 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
diff --git a/ethcore/res/ethereum/tests b/ethcore/res/ethereum/tests
index 97066e40c..9028c4801 160000
--- a/ethcore/res/ethereum/tests
+++ b/ethcore/res/ethereum/tests
@@ -1 +1 @@
-Subproject commit 97066e40ccd061f727deb5cd860e4d9135aa2551
+Subproject commit 9028c4801fd39fbb71a9796979182549a24e81c8
diff --git a/ethstore/src/dir/disk.rs b/ethstore/src/dir/disk.rs
index 6616ec15d..56b2c1ccb 100644
--- a/ethstore/src/dir/disk.rs
+++ b/ethstore/src/dir/disk.rs
@@ -20,6 +20,7 @@ use std::collections::HashMap;
 use time;
 use ethkey::Address;
 use {json, SafeAccount, Error};
+use json::UUID;
 use super::KeyDirectory;
 
 const IGNORED_FILES: &'static [&'static str] = &["thumbs.db", "address_book.json"];
@@ -112,7 +113,7 @@ impl KeyDirectory for DiskDirectory {
 		// build file path
 		let filename = account.filename.as_ref().cloned().unwrap_or_else(|| {
 			let timestamp = time::strftime("%Y-%m-%dT%H-%M-%S", &time::now_utc()).expect("Time-format string is valid.");
-			format!("UTC--{}Z--{:?}", timestamp, account.address)
+			format!("UTC--{}Z--{}", timestamp, UUID::from(account.id))
 		});
 
 		// update account filename
diff --git a/js/package.json b/js/package.json
index 59b75c591..2a2b6d590 100644
--- a/js/package.json
+++ b/js/package.json
@@ -1,6 +1,6 @@
 {
   "name": "parity.js",
-  "version": "0.2.49",
+  "version": "0.2.50",
   "main": "release/index.js",
   "jsnext:main": "src/index.js",
   "author": "Parity Team <admin@parity.io>",
@@ -122,6 +122,7 @@
     "brace": "^0.9.0",
     "bytes": "^2.4.0",
     "chart.js": "^2.3.0",
+    "es6-error": "^4.0.0",
     "es6-promise": "^3.2.1",
     "ethereumjs-tx": "^1.1.2",
     "file-saver": "^1.3.3",
diff --git a/js/scripts/release.sh b/js/scripts/release.sh
index 5e631cf98..3ff4a577c 100755
--- a/js/scripts/release.sh
+++ b/js/scripts/release.sh
@@ -68,11 +68,13 @@ if [ "$BRANCH" == "master" ]; then
 fi
 
 echo "*** Updating cargo parity-ui-precompiled#$PRECOMPILED_HASH"
+git submodule update
 cargo update -p parity-ui-precompiled
 # --precise "$PRECOMPILED_HASH"
 
 echo "*** Committing updated files"
-git add .
+git add js
+git add Cargo.lock
 git commit -m "[ci skip] js-precompiled $UTCDATE"
 git push origin HEAD:refs/heads/$BRANCH 2>$GITLOG
 
diff --git a/js/src/api/transport/error.js b/js/src/api/transport/error.js
new file mode 100644
index 000000000..341839f69
--- /dev/null
+++ b/js/src/api/transport/error.js
@@ -0,0 +1,53 @@
+// Copyright 2015, 2016 Ethcore (UK) Ltd.
+// This file is part of Parity.
+
+// Parity is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity.  If not, see <http://www.gnu.org/licenses/>.
+
+import ExtendableError from 'es6-error';
+
+export const ERROR_CODES = {
+  UNSUPPORTED_REQUEST: -32000,
+  NO_WORK: -32001,
+  NO_AUTHOR: -32002,
+  NO_NEW_WORK: -32003,
+  NOT_ENOUGH_DATA: -32006,
+  UNKNOWN_ERROR: -32009,
+  TRANSACTION_ERROR: -32010,
+  EXECUTION_ERROR: -32015,
+  ACCOUNT_LOCKED: -32020,
+  PASSWORD_INVALID: -32021,
+  ACCOUNT_ERROR: -32023,
+  SIGNER_DISABLED: -32030,
+  DAPPS_DISABLED: -32031,
+  NETWORK_DISABLED: -32035,
+  REQUEST_REJECTED: -32040,
+  REQUEST_REJECTED_LIMIT: -32041,
+  REQUEST_NOT_FOUND: -32042,
+  COMPILATION_ERROR: -32050,
+  ENCRYPTION_ERROR: -32055,
+  FETCH_ERROR: -32060
+};
+
+export default class TransportError extends ExtendableError {
+  constructor (method, code, message) {
+    const m = `${method}: ${code}: ${message}`;
+    super(m);
+
+    this.code = code;
+    this.type = Object.keys(ERROR_CODES).find((k) => ERROR_CODES[k] === code) || '';
+
+    this.method = method;
+    this.text = message;
+  }
+}
diff --git a/js/src/api/transport/http/http.js b/js/src/api/transport/http/http.js
index 8ea59f0fb..591b9a627 100644
--- a/js/src/api/transport/http/http.js
+++ b/js/src/api/transport/http/http.js
@@ -16,6 +16,7 @@
 
 import { Logging } from '../../subscriptions';
 import JsonRpcBase from '../jsonRpcBase';
+import TransportError from '../error';
 
 /* global fetch */
 export default class Http extends JsonRpcBase {
@@ -73,7 +74,8 @@ export default class Http extends JsonRpcBase {
           this.error(JSON.stringify(response));
           console.error(`${method}(${JSON.stringify(params)}): ${response.error.code}: ${response.error.message}`);
 
-          throw new Error(`${method}: ${response.error.code}: ${response.error.message}`);
+          const error = new TransportError(method, response.error.code, response.error.message);
+          throw error;
         }
 
         this.log(JSON.stringify(response));
diff --git a/js/src/api/transport/index.js b/js/src/api/transport/index.js
index 8f67fba4d..84fbac826 100644
--- a/js/src/api/transport/index.js
+++ b/js/src/api/transport/index.js
@@ -16,3 +16,4 @@
 
 export Http from './http';
 export Ws from './ws';
+export TransportError from './error.js';
diff --git a/js/src/api/transport/ws/ws.js b/js/src/api/transport/ws/ws.js
index d608426b0..1cb1fb1c4 100644
--- a/js/src/api/transport/ws/ws.js
+++ b/js/src/api/transport/ws/ws.js
@@ -18,6 +18,7 @@ import { keccak_256 } from 'js-sha3'; // eslint-disable-line camelcase
 
 import { Logging } from '../../subscriptions';
 import JsonRpcBase from '../jsonRpcBase';
+import TransportError from '../error';
 
 /* global WebSocket */
 export default class Ws extends JsonRpcBase {
@@ -109,7 +110,9 @@ export default class Ws extends JsonRpcBase {
 
         console.error(`${method}(${JSON.stringify(params)}): ${result.error.code}: ${result.error.message}`);
 
-        reject(new Error(`${method}: ${result.error.code}: ${result.error.message}`));
+        const error = new TransportError(method, result.error.code, result.error.message);
+        reject(error);
+
         delete this._messages[result.id];
         return;
       }
diff --git a/js/src/modals/DeployContract/deployContract.js b/js/src/modals/DeployContract/deployContract.js
index a99b49412..996948092 100644
--- a/js/src/modals/DeployContract/deployContract.js
+++ b/js/src/modals/DeployContract/deployContract.js
@@ -26,6 +26,8 @@ import ErrorStep from './ErrorStep';
 
 import styles from './deployContract.css';
 
+import { ERROR_CODES } from '../../api/transport/error';
+
 const steps = ['contract details', 'deployment', 'completed'];
 
 export default class DeployContract extends Component {
@@ -63,7 +65,8 @@ export default class DeployContract extends Component {
     params: [],
     paramsError: [],
     step: 0,
-    deployError: null
+    deployError: null,
+    rejected: false
   }
 
   componentWillMount () {
@@ -92,15 +95,20 @@ export default class DeployContract extends Component {
   }
 
   render () {
-    const { step, deployError } = this.state;
+    const { step, deployError, rejected } = this.state;
+
+    const realSteps = deployError || rejected ? null : steps;
+    const title = realSteps
+      ? null
+      : (deployError ? 'deployment failed' : 'rejected');
 
     return (
       <Modal
         actions={ this.renderDialogActions() }
         current={ step }
-        steps={ deployError ? null : steps }
-        title={ deployError ? 'deployment failed' : null }
-        waiting={ [1] }
+        steps={ realSteps }
+        title={ title }
+        waiting={ realSteps ? [1] : null }
         visible
         scroll>
         { this.renderStep() }
@@ -158,7 +166,7 @@ export default class DeployContract extends Component {
 
   renderStep () {
     const { accounts, readOnly } = this.props;
-    const { address, deployError, step, deployState, txhash } = this.state;
+    const { address, deployError, step, deployState, txhash, rejected } = this.state;
 
     if (deployError) {
       return (
@@ -166,6 +174,15 @@ export default class DeployContract extends Component {
       );
     }
 
+    if (rejected) {
+      return (
+        <BusyStep
+          title='The deployment has been rejected'
+          state='You can safely close this window, the contract deployment will not occur.'
+        />
+      );
+    }
+
     switch (step) {
       case 0:
         return (
@@ -273,6 +290,11 @@ export default class DeployContract extends Component {
         });
       })
       .catch((error) => {
+        if (error.code === ERROR_CODES.REQUEST_REJECTED) {
+          this.setState({ rejected: true });
+          return false;
+        }
+
         console.error('error deploying contract', error);
         this.setState({ deployError: error });
         store.dispatch({ type: 'newError', error });
diff --git a/js/src/modals/ExecuteContract/executeContract.js b/js/src/modals/ExecuteContract/executeContract.js
index b45cf6875..a57c18a1d 100644
--- a/js/src/modals/ExecuteContract/executeContract.js
+++ b/js/src/modals/ExecuteContract/executeContract.js
@@ -23,6 +23,8 @@ import { validateAddress, validateUint } from '../../util/validation';
 
 import DetailsStep from './DetailsStep';
 
+import { ERROR_CODES } from '../../api/transport/error';
+
 export default class ExecuteContract extends Component {
   static contextTypes = {
     api: PropTypes.object.isRequired,
@@ -49,7 +51,8 @@ export default class ExecuteContract extends Component {
     step: 0,
     sending: false,
     busyState: null,
-    txhash: null
+    txhash: null,
+    rejected: false
   }
 
   componentDidMount () {
@@ -80,6 +83,7 @@ export default class ExecuteContract extends Component {
     const { onClose, fromAddress } = this.props;
     const { sending, step, fromAddressError, valuesError } = this.state;
     const hasError = fromAddressError || valuesError.find((error) => error);
+
     const cancelBtn = (
       <Button
         key='cancel'
@@ -115,7 +119,16 @@ export default class ExecuteContract extends Component {
 
   renderStep () {
     const { onFromAddressChange } = this.props;
-    const { step, busyState, txhash } = this.state;
+    const { step, busyState, txhash, rejected } = this.state;
+
+    if (rejected) {
+      return (
+        <BusyStep
+          title='The execution has been rejected'
+          state='You can safely close this window, the function execution will not occur.'
+        />
+      );
+    }
 
     if (step === 0) {
       return (
@@ -221,7 +234,17 @@ export default class ExecuteContract extends Component {
       })
       .then((requestId) => {
         this.setState({ busyState: 'Waiting for authorization in the Parity Signer' });
-        return api.pollMethod('parity_checkRequest', requestId);
+
+        return api
+          .pollMethod('parity_checkRequest', requestId)
+          .catch((e) => {
+            if (e.code === ERROR_CODES.REQUEST_REJECTED) {
+              this.setState({ rejected: true });
+              return false;
+            }
+
+            throw e;
+          });
       })
       .then((txhash) => {
         this.setState({ sending: false, step: 2, txhash, busyState: 'Your transaction has been posted to the network' });
diff --git a/js/src/modals/Transfer/transfer.js b/js/src/modals/Transfer/transfer.js
index d27fdd2b4..e41ea08f9 100644
--- a/js/src/modals/Transfer/transfer.js
+++ b/js/src/modals/Transfer/transfer.js
@@ -28,13 +28,16 @@ import Extras from './Extras';
 import ERRORS from './errors';
 import styles from './transfer.css';
 
+import { ERROR_CODES } from '../../api/transport/error';
+
 const DEFAULT_GAS = '21000';
 const DEFAULT_GASPRICE = '20000000000';
 const TITLES = {
   transfer: 'transfer details',
   sending: 'sending',
   complete: 'complete',
-  extras: 'extra information'
+  extras: 'extra information',
+  rejected: 'rejected'
 };
 const STAGES_BASIC = [TITLES.transfer, TITLES.sending, TITLES.complete];
 const STAGES_EXTRA = [TITLES.transfer, TITLES.extras, TITLES.sending, TITLES.complete];
@@ -74,7 +77,8 @@ export default class Transfer extends Component {
     valueAll: false,
     valueError: null,
     isEth: true,
-    busyState: null
+    busyState: null,
+    rejected: false
   }
 
   componentDidMount () {
@@ -82,13 +86,19 @@ export default class Transfer extends Component {
   }
 
   render () {
-    const { stage, extras } = this.state;
+    const { stage, extras, rejected } = this.state;
+
+    const steps = [].concat(extras ? STAGES_EXTRA : STAGES_BASIC);
+
+    if (rejected) {
+      steps[steps.length - 1] = TITLES.rejected;
+    }
 
     return (
       <Modal
         actions={ this.renderDialogActions() }
         current={ stage }
-        steps={ extras ? STAGES_EXTRA : STAGES_BASIC }
+        steps={ steps }
         waiting={ extras ? [2] : [1] }
         visible
         scroll
@@ -133,7 +143,16 @@ export default class Transfer extends Component {
   }
 
   renderCompletePage () {
-    const { sending, txhash, busyState } = this.state;
+    const { sending, txhash, busyState, rejected } = this.state;
+
+    if (rejected) {
+      return (
+        <BusyStep
+          title='The transaction has been rejected'
+          state='You can safely close this window, the transfer will not occur.'
+        />
+      );
+    }
 
     if (sending) {
       return (
@@ -455,7 +474,17 @@ export default class Transfer extends Component {
         : this._sendToken()
       ).then((requestId) => {
         this.setState({ busyState: 'Waiting for authorization in the Parity Signer' });
-        return api.pollMethod('parity_checkRequest', requestId);
+
+        return api
+          .pollMethod('parity_checkRequest', requestId)
+          .catch((e) => {
+            if (e.code === ERROR_CODES.REQUEST_REJECTED) {
+              this.setState({ rejected: true });
+              return false;
+            }
+
+            throw e;
+          });
       })
       .then((txhash) => {
         this.onNext();
diff --git a/js/src/ui/Errors/errors.css b/js/src/ui/Errors/errors.css
index 30fd7186a..216993e4f 100644
--- a/js/src/ui/Errors/errors.css
+++ b/js/src/ui/Errors/errors.css
@@ -17,4 +17,10 @@
 
 .container {
   z-index: 10101 !important;
+
+  button {
+    color: white !important;
+    margin: 0 !important;
+    margin-right: -16px !important;
+  }
 }
diff --git a/js/src/ui/Errors/errors.js b/js/src/ui/Errors/errors.js
index e29e002b9..fe23a6f40 100644
--- a/js/src/ui/Errors/errors.js
+++ b/js/src/ui/Errors/errors.js
@@ -23,9 +23,12 @@ import { closeErrors } from './actions';
 
 import styles from './errors.css';
 
+const ERROR_REGEX = /-(\d+): (.+)$/;
+
 class Errors extends Component {
   static propTypes = {
     message: PropTypes.string,
+    error: PropTypes.object,
     visible: PropTypes.bool,
     onCloseErrors: PropTypes.func
   };
@@ -37,22 +40,60 @@ class Errors extends Component {
       return null;
     }
 
+    const text = this.getErrorMessage();
+
     return (
       <Snackbar
-        open
         className={ styles.container }
-        message={ message }
-        autoHideDuration={ 5000 }
-        onRequestClose={ onCloseErrors } />
+        open
+        action='close'
+        autoHideDuration={ 60000 }
+        message={ text }
+        onActionTouchTap={ onCloseErrors }
+        onRequestClose={ this.onRequestClose }
+        bodyStyle={ {
+          whiteSpace: 'pre-line',
+          height: 'auto'
+        } }
+        contentStyle={ {
+          display: 'flex',
+          flexDirection: 'row',
+          lineHeight: '1.5em',
+          padding: '0.75em 0',
+          alignItems: 'center'
+        } }
+      />
     );
   }
+
+  getErrorMessage = () => {
+    const { message, error } = this.props;
+
+    if (!error.text && !ERROR_REGEX.test(message)) {
+      return message;
+    }
+
+    const matches = ERROR_REGEX.exec(message);
+
+    const code = error.code || parseInt(matches[1]) * -1;
+    const text = error.text || matches[2];
+
+    return `[${code}] ${text}`;
+  }
+
+  onRequestClose = (reason) => {
+    if (reason === 'timeout') {
+      this.props.onCloseErrors();
+    }
+  }
 }
 
 function mapStateToProps (state) {
-  const { message, visible } = state.errors;
+  const { message, error, visible } = state.errors;
 
   return {
     message,
+    error,
     visible
   };
 }
diff --git a/js/src/ui/Errors/reducers.js b/js/src/ui/Errors/reducers.js
index f04a7529d..ed4fcba34 100644
--- a/js/src/ui/Errors/reducers.js
+++ b/js/src/ui/Errors/reducers.js
@@ -19,7 +19,8 @@ function newError (state, action) {
 
   return Object.assign({}, state, {
     visible: true,
-    message: error.message
+    message: error.message,
+    error
   });
 }