Spambot Error Log Crisis - Does Anti Bot mod Work?

[planetxtownhall]

My forum registration requires three security answers and moderator approval.  That is blocking the spambots from creating accounts or posting, but the problem is my error log.  The forum is big and I'm tens of thousands of error log messages each day.  When the error log gets too big, Godaddy shuts down my SQL connection so now I'm having to purge the error log every few days. 

I'm looking at the Anti Bot: Unrecognizable Form mod as a possibility.  Does anyone have any ideas?

Here is a typical entry from my error log:

Guest
Apply Filter: Only show the error messages of this IP address 46.229.168.143   

Today at 01:41:06 PM
Apply Filter: Only show the error messages of this session 2df0b6952e89b809b8106cb2bd6e585e
Apply Filter: Only show the errors of this type Type of error: General

hxxp:planetxtownhall.com/index.php?/topic,7128.0.html [nonactive]
Apply Filter: Only show the errors with the same message
8192: Function create_function() is deprecated
Apply Filter: Only show the errors from this file
File: /home/xxxxxxxxx/public_html/pxth/Sources/Subs.php
Line: 1595

The spambots change or spoof a different IP each day. 

I'm running 2.0.15 and I tried setting error log pruning to 1 day.  That didn't work.

Help, please.  Could someone throw me a bone here?

Thanks, Marshall

[shawnb61]

Are you running PHP 7.2?  If so, you may need to change back to PHP 7.1.

PHP 7.2 is not supported by SMF 2.0.x at this time.   

[Kindred]

Also, if you have 3 questions, do you only have 3 questions and ask 3 questions? If that is true then your questions have been cataloged and are being answered by the bots. You have to set new questions. I suggest adding 20 to 30 questions and asking 2