First off I use PHP 5.4.41 and MySQL 5.1.73 with no problems

See https://stackoverflow.com/questions/2706498/mysql-error-1064

@amoun wrote earlier:

First off I use PHP 5.4.41 and MySQL 5.1.73 with no problems

See https://stackoverflow.com/questions/2706498/mysql-error-1064

Thanks, I just took a look at that page, but I'm not a MySQL guru so it's not clear to me exactly what I need to do to fix the error.

When you show the code of the error it's just an image. If you can copy the code and insert it so the whole code can be scrolled, to see everything, someone may spot a syntax error, as in the example I linked to. Though I have doubts about that as it's code that is part of the blog engine which works fine elsewhere. Still by ruling it out something else may come to light.

@michaelz as @amoun said, please copy/paste the whole error message here, because it references a part of the code that we can't see in your screenshot.

Regards!

To generate the error message again, I had to wait until I could try another upgrade attempt. I just did another standard (manual) upgrade, but this time it succeeded. I'm not sure why it worked this time and not earlier, as I followed the exact same procedure (verifying the database through the install script, deleting all old non-custom b2evo files, etc.) but in any case, the issue is resolved.