[TYPO3-commerce] Fatal Error after update 0.12.7 to 0.13.12

[Ueli Niggli]

Hello everyone

I am currently updating a typo3 installation which has not been touched for some time. The core is 4.6.3 and the commerce in 0.12.7. After updating to 0.13.12 with the extension manager, the ext. manager can't be started and the following error is displayed:

Fatal error: Class 'tx_commerce_element_alib' not found in /home/httpd/vhosts/uska.ch/subdomains/testing/httpdocs/typo3conf/ext/commerce/lib/class.tx_commerce_article_price.php on line 33

Is this a known problem?

Second question, if I manage to sort out all these problems will I be able to run commerce with 6.2 or is it smarter to first go to 6.1?

best regards and thank you in advance,

Ueli