Thank you for the response.
The version I am using is 7.5.8, which I assume is the most current. We just purchased the software in March.
The link you provided essentially describes the problem I am having.
I was referring to my own permissions as admin... when the zeroing event happened spontaneously, I had attempted to give myself editing permissions through forum settings of one particular forum, clicked to update permissions and when the screen returned, I found that I was suddenly unable to read any posts on any forums. At that point, I was unable to execute a permission change through forum settings or group settings.
I'll recheck the read/write file permissions, but I think those were correct.
I will also check to see if the hosting server updated the default PHP version lately... that sounds like the best clue.
