[TYPO3-english] Error on updating from TYPO3 6.1 to 6.2

[Chris Müller]

Hi,

I want to update my TYPO3 installation from version 6.1.7 to 6.2.1.

I changed the symlink of typo3_src to the new core, deleted the t3lib
symlink and called the install tool. I am getting the following error:

PHP Fatal error:  Undefined class constant 'LOCKING_METHOD_SIMPLE' in
<removed>/typo3_src-6.2.1/typo3/sysext/core/Classes/Core/ClassLoader.php
on line 756

I tried the same with 6.2.0 and got the same error. I don't have a clue
what to do. I deleted also the typo3temp/Cache/ folder.

Google only showed me an IRC conversion with this error, but there was
no answer about it.

Any hints?

Regards,
Chris.