I have just tried to ugrade to newest version 0.6.14100 (light) but such error occured:
I have several products with custom attribute set defined.
Deleting Core/GiftMessage directory makes store working (except orders admin area)
Ok, in order to upgrade to the latest version you can just temporary rename that group as it was by default - ‘General’, put the GiftMessage module files in their places, upgrade and then change that group name back to “Ogólne”.
The problem is that new attributes are added to the attribute group “General” by its name. We’ll fix this in the next releases.
Thank you, thank you, thank you. I was having a catalog wrong attribute ID error, that’s been crashing my site for the 4 days. replacing *.abc for *.php cleared up the issue. It didn’t solve it, but at least my site works now.