I inadvertently made this worse today by trying to disable the " HTML in posts " plugin that's responsible (at Yvonne's suggestion). There seems to be a bug in the disable/enable function, so disabling made things much worse, and reenabling didn't bring things back to the previous state.
I suspect the board software needs a reinstall without going anywhere near that plugin. After that, you'll probably still see HTML gunk in old posts made while the plugin was present, but older and newer posts should be okay.
Unfortunately I don't have experience with installing MyBB.
I suspect the board software needs a reinstall without going anywhere near that plugin. After that, you'll probably still see HTML gunk in old posts made while the plugin was present, but older and newer posts should be okay.
Unfortunately I don't have experience with installing MyBB.