Hi I've tried upgrading my 1.11 to 1.14 and get this "illegal mix of collations" error. I went through the normal upgrade procedure first but this failed, so I then tried exporting as XML and importing into a completely fresh 1.14 install, and still I get the error!
I've found that by setting $wgDBmysql5 to false things seem to work ok, but is this really a good solution? I'd like everything to be running up to date, not in some backward compatibility mode... does anyone have any idea how to fix the problem properly?