Quote from: ibminer on May 10, 2016, 03:47:40 PM

So my guess would be that some of this post is getting cut off due to posting character limits and its breaking the code wherever its cutting it off at and messing up the table(s)

Yeah, that's what it is. Posts over 65535 bytes get cut off at 65535 bytes. If that makes the BBcode invalid in certain ways, then you get the INVALID BBCODE error.

Also, note that a byte is different from a character. Because SMF stores "special" characters in a particularly space-inefficient way, each Russian character uses about 6 bytes, and each line break also uses 6 bytes.