I also had the route changer by @Jake Bunce installed before and now lots of links both internal and incoming are resolving as errors. I have a few examples below...
https://www.mydomain.com/forums/view/main_forum/ - old
https://www.mydomain.com/forums/main_forum/ - new
https://www.mydomain.com/forums/threads/thread-one/ - old
https://www.mydomain.com/threads/thread-one/ - new
What's the best way have the incoming links redirect to the new structure and is there a way to change any find and replace any links inside the forum itself.