[TYPO3-dev] TYPO3.7: Module half registered? Bug?

[Rene K]

Hello,

I have a problem with an old plugin (ab_downloads) and I want patch it to run in TYPO3 7.6.
The module is registered and shows up in the panel under "web".

But: No TYPO3 classes are available, so it can not run.

> get_declared_classes() shows only PHP-internal classes.
> get_defined_constants() shows not any TYPO3-constant.

And: Another old plugin (wec_map) with modules is running properly instead.

wec_map:  
\TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addModule('tools','txwecmapM1','',\TYPO3\CMS\Core\Utility\ExtensionManagementUtility::extPath($_EXTKEY).'mod1/');
-> works, all classes & constants available

ab_downloads:  
\TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addModule('web','txabdownloadsM1','',\TYPO3\CMS\Core\Utility\ExtensionManagementUtility::extPath($_EXTKEY).'mod1/');
-> fails, no classes & no constants available - an "empty" script without any TYPO3-bootstrap is executed.

What the hell is going on? Would you mean it is a bug?
I'm using the compatilibity6 layer too.

PHP-Log says everything works fine till the module is loaded and dies with "class TYPO3\CMS\Core\Utility\GeneralUtility not found". (because not a single class is loaded).

But I understand not why. Both plugins uses the same technique to register the module.