I upgraded and got the problem too. Whythis problem has come? I don't know but I use MySQL 5.0.22.
I downloaded my database, converted it and instead of using my old templates (which I had done a hell of work on) I started changing the new ones.
Among others I changed on last discussions page and on topic page the order 1. replies 2.Views 3.Author 4.Latest reply to 126.96.36.199 and cut off the hour and seconds.
I tried nearly everything again and again and validated with w3c. All seamed fine and all my old groups, messages etc were intact
I then went on and installed Captcha, but now I understood that I had forgotten the important thing to try to post! I discovered now thaT I couldn't.
Naturally I thought that I had done something wrong with Captcha, but as I could not find any failure I uninstalled it.
Still I could not post so I was sure I had done a mistake by my messing around and began changing 'my'own' templates back to the originals one by one.
It did not help and I then took the whole original MiniBB instead of 'my own' and everything worked as before with my data etc. and there was still something wrong.
I found that both in the original and in 'my own' I could post answers to a topic but that I could not post a new topic.
When I try to post a new topic I get exactly the same message Field 'topic_last_post_time' doesn't have a default value.
So, what to do now?
The solution above seems simple, but what is the _topics table? Where exactly shall I put the code?
I can't find field "topic_last_post_time in main_topic or in main_topic_cell. I can only find it in 4 files (Bbfunc_pthread_ , Bbfunc_delmsg , Bb_admin and in _install_mysql).
Again, whythis problem has come? I don't know and suddently I can't remember what I did in the first place. I know that I used the upgrade database thing but I don't think (but can't remember) that I used _install:mysql at all and in which you see' the solution' topic_last_post_time datetime not null default '0000-00-00 00:00:00'".
Anyway, it looks for me as my database is quite correct, I mean all the stuff with the time is there.
Can one of you please show me, a kind of a newbee, precise where I put the solution?