Are you still unable to edit posts by chance?

This is happening because the forum post is so large. Unfortunately, we have experienced some unexpected problems with long forum posts lagging when you go to edit them. This is a known issue but unfortunately not easy to solve, since the problem is that too much data is being transmitted, and it's lags too long.

I know it's a workaround, not a solution, but you could try to split it into multiple forum posts elsewhere, like inside a forum group, for now. Sorry for the inconvenience D: