This wasn't working for me, the sqlitedberrors file wasn't writeable despite having the correct permissions. Maybe this was due to some obscure setting on our hardened-security server. Fortunately I found the solution by following the advice of another person with the same problem, they posted the solution on the VB3 version of this mod :
https://vborg.vbsupport.ru/showpost....9&postcount=47
Using that post's advice, I moved the sqlitedberrors file to a subdirectory and adjusted the path in the code, the problem was immediately solved.
ps. earlier in this thread someone asked about how to test this mod and a suggestion was to stop the SQL server. That would work but for most people it's probably easier to just edit the /includes/config.php and change the database settings to give an incorrect username. Then visit your forum homepage 5 times, if you get more than 1 email then this mod isn't working.
Thanks for the great mod, I'm using it with 4.0.8 and can't believe this STILL hasn't been included in core.