[TYPO3-extbase-kickstarter] roundtrip feature: Extension could not be saved...

[Roland]

hello everybody,

i use the extension builders (2.0.5 on TYPO3 4.5.7) "roundtrip" feature 
and get this error message when trying to save the domain model of my 
extension:

--- quote ---
Extension could not be saved: Could not write ext_tables.sql, error: 
File 
/Applications/XAMPP/xamppfiles/htdocs/geb-website/typo3conf/ext/gebprodukte/ext_localconf.php 
could not be created!
--- /quote ---

what went wrong?

further information:

i created the domain model a few days ago. everything worked like 
expected. today i added 2 objects (including some relations to already 
existing objects). i saved the domain model: everything worked like 
expected.

as i did not set up the yaml file properly (and already modified some of 
the extensions files last week) i had to revert some of the 
modifications the extension builder made on my extension via git. 
nothing special, only some tca adjustments, etc.

now i tried to modify the domain model once again (change relation types 
of some of the relations of one of the two new objects) and got the 
error message i mentioned above.

strangely i also get the error message if i do not change anything of my 
domain model: load domain model >> save domain model >> error message.

kind regards

roland