[TYPO3-commerce] Unsupported operand types Error in moneylib

[Sebastian Stanger]

Hello List,

since a few days I receive the following error in typo3-commerce.

Fatal error: Unsupported operand types in 
/PATH/cms/typo3conf/ext/moneylib/class.tx_moneylib.php on line 100

The strange thing is, that it only occures on a few categories.

Has anyone a solution for this or any other idea?

Best regards,

Sebastian