[TYPO3-commerce] Problems after Update 4.7.8 - blank pages

[Michael Hansky]

Hello 
i got problems after Updating from 4.5.x to 4.7.8.

At the moment i use commerce 0.12.7

With this combination, i got a blank page after the last step of the check-out and no mail will be sent.
(Browser says: 500 internal error)

When i update to commerce 0.13.08 /0.13.12 i get additional problems with the basket: 
another blank page will appear when i open it.

Its strange, because when i give that content element a "QUICKVIEV" in Plug-In-Modus,
the normal page with the small basket is displayed.


You can take a look under 
http://www.bodenseekur.de/index.php?id=25
(orders will be ignored)

thx for answers
Michael