TYPO3 Core

I did execute the check for broken extensions because extensions for TYPO3 6.2 had been installed and I wanted to check and maybe unstall them from the Install Tool.
Now I updated one of those extensions by FTP and the Extension Manager and the Install Tool error warning is gone.
I still think this is a TYPO3 Install Tool issue. The "check of broken extensions" should offer the broken extension to uninstall them.

well, the 'check for broken extensions' only allows to unload extension that it actually detects as faulty. the 'broken ext check' only tests ext_localconf and ext_tables loading, nothing more - this is NOT a foolproof system to check every detail of an extension: it basically only takes care that probably you backend will not fatal anymore after an upgrade (in case no extension has additional low-level backend hooks that also may fatal a backend call).

if i read you correctly franz, you propose a functionality in the install tool to force unloading any extension (except the protected ones). i think that would actually be a useful feature. would be nice to have that.

But if an extension raises an exception then this could be detected and reported as well by the Install Tool.
The feature to unload the extensions would be nice. However if it is done automatically then there should be a notice or a log file entry for the user in order to tell him which extensions have been deinstalled.

Well no, the install tool can not check if some extension raises an exception in any use case.