I installed the Typo3 version 7.6 and After adding extension to my page i got the error "Oops, an error occurred! Code: 201512031647523f4d731f". I am not getting meaning of this error and i also enable 'displayErrors' => 1, in local configuration but still not get meaningful error.
You need to switch off the "Content Object Exception Handler", which is an exception handler in new versions. If a content element/plugin throws an exception, it does no longer take down the whole site, but only itself. To disable it, set
config.contentObjectExceptionHandler = 0
Don't forget to re-enable the exception handler when going live, and in your live system, you can find the exception trace in your log files. Basically what Viktor Livakivskyi says in the other answer.
Basically it is date + hash, which makes each of such errors unique.
For development environment you may turn it off, as @Jost suggested.
But for production this is crucial to let it be turned on, so if some of your plugins or TS libs fails, it will not break the complete output and show "Oops an error occurred" without any info, but the message, you see now with a code.
The real user of a website can then report this code to you, and you can search for this code in your TYPO3 error log, which is by default located under typo3temp/logs/, unless you configured it different.
So, this feature really easies your life to find out user-generated errors.
You can open the file ./typo3/sysext/frontend/Classes/ContentObject/Exception/ProductionExceptionHandler.php
Search for the string Oops, an error occurred!. Add a debug line directly after the function declaration.
/**
* Handles exceptions thrown during rendering of content objects
* The handler can decide whether to re-throw the exception or
* return a nice error message for production context.
*
* @param \Exception $exception
* @param AbstractContentObject $contentObject
* @param array $contentObjectConfiguration
* @return string
* @throws \Exception
*/
public function handle(\Exception $exception, AbstractContentObject $contentObject = null, $contentObjectConfiguration = array())
{
debug ($exception, 'handle $exception');
Then you use a debug extension, e.g. fh_debug. This will give you an output like this. It shows you the backtrace of the call which lead to this error. The backtraces are shown in 2 formats. You can add more debug lines at the positions before the places from the backtraces, in order to have more information about the error.
<table><tbody><tr><td>index.php</td><td>34</td><td>call_user_func</td></tr><tr><td>index.php</td><td>33</td><td>run</td></tr><tr><td>Application.php</td><td>78</td><td>handleRequest</td></tr><tr><td>Bootstrap.php</td><td>302</td><td>handleRequest</td></tr><tr><td>RequestHandler.php</td><td>232</td><td>INTincScript</td></tr><tr><td>TypoScriptFrontendController.php</td><td>3478</td><td>recursivelyReplaceIntPlaceholdersInContent</td></tr><tr><td>TypoScriptFrontendController.php</td><td>3512</td><td>INTincScript_process</td></tr><tr><td>TypoScriptFrontendController.php</td><td>3564</td><td>cObjGetSingle</td></tr><tr><td>ContentObjectRenderer.php</td><td>859</td><td>render</td></tr><tr><td>ContentObjectRenderer.php</td><td>943</td><td>render</td></tr><tr><td>ContentObjectArrayContentObject.php</td><td>41</td><td>cObjGet</td></tr><tr><td>ContentObjectRenderer.php</td><td>805</td><td>cObjGetSingle</td></tr><tr><td>ContentObjectRenderer.php</td><td>859</td><td>render</td></tr><tr><td>ContentObjectRenderer.php</td><td>953</td><td>handle</td></tr><tr><td>ProductionExceptionHandler.php</td><td>53</td><td>debug</td></tr></tbody></table><br><table><tbody><tr><th>Object TYPO3\CMS\Core\Error\Exception</th></tr><tr><td>message</td><td class="el">PHP Catchable Fatal Error: Argument 1 passed to TYPO3\CMS\Frontend\ContentObject\ContentObjectRenderer::render() must be an instance of TYPO3\CMS\Frontend\ContentObject\AbstractContentObject, null given, called in /home/myuser/public_html/neu/typo3_src-7.6.10/typo3/sysext/frontend/Classes/ContentObject/ContentObjectRenderer.php on line 1359 and defined in /home/myuser/public_html/neu/typo3_src-7.6.10/typo3/sysext/frontend/Classes/ContentObject/ContentObjectRenderer.php line 927</td></tr>
<tr><td>code</td><td class="el"><table><tbody><tr><th>Integer</th></tr><tr><td>1</td></tr></tbody></table></td></tr>
<tr><td>file</td><td class="el">/home/myuser/public_html/neu/typo3_src-7.6.10/typo3/sysext/core/Classes/Error/ErrorHandler.php</td></tr>
<tr><td>line</td><td class="el"><table><tbody><tr><th>Integer</th></tr><tr><td>111</td></tr></tbody></table></td></tr>
</tbody></table>
<h3>handle $exception</h3><hr>Text, added later: In the meantime it is not necessary any more to edit the PHP file ProductionExceptionHandler.php of TYPO3. You just install and configure the extension fh_debug which now does the necessary step automatically.
来源：https://stackoverflow.com/questions/34064691/oops-an-error-occurred-code-201601301501048-in-typo3-7-6