This was one of those known problems on the old system (duplicated forums/posts/threads) where if someone wanted to be malicious (we had a few cases) someone could have created a forum with the same name making the original forum unaccessable. It would not change or ove write the information but the way the URL structure was read just mean you would not be able to access it. This was one of those discussions on how do we fix it and not disrupt the site and honestly this was the best solution as it resolved some issues with duplicate names that already existed that we were fighting but it also eliviated the problem going forward.
The current structure is locked and will nto be changing so you can bookmark this and know you will be able to come back painlessly.
Sorry for the inconvinience
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