This isn't the bug where if you have a layer marked as "mixed", the router will crash.
I have a board that i have been freeRouting in the past. It had been unable to complete the last 70 or so connections. I had made some changes and routed some connections manually and created a new DSN file. FreeRouter will no longer load the file; the "Loading..." popup message box stays up indefinitely. I have left it running, trying to load, for more than 24 hours several times.
My Intercomm application loads the DSN file just fine and in seconds. The file is now over 250Kb in size.