Thread randomly split up?

A couple of months ago a thread on my forum was, for some reason, split up into two threads. The thread was still in use, and was over 70 pages long.

One day, I logged on to the forum, and saw that there were now two threads, one of them being stickied (like the original), which contained the 8 most recent pages, and another one containing the other 67 pages, which was locked. I did not manually split it up (I wouldn't even know how to do that), and as far as I know none of my moderators caused this.

The last post in the locked thread was one of my posts, which had been edited: the original content was there, followed by this:

Aegonian wrote:
*original content

-------

*link to stickied thread

The thread isn't in use anymore (it was a roleplay thread, and the roleplay ended quite some time ago), but I'd like to know if anyone knows what could have caused this, and if so, how to prevent it from happening again to other threads.

Hi,

There's a limit. A thread can only have 990 posts, and it automatically locks, and starts a new one.

Ah, that explains it, thanks!