convoy replacing mostly works, but sometimes with no apparent reasons trains will empty and continue to go without entering the depo.
also, when there is more than one depot, trains will get confused and not know where to go. a 'depo cannot be found' message may pop up many many times after a while.
http://simutrans-germany.com/files/upload/bug-replacing.sve (http://simutrans-germany.com/files/upload/bug-replacing.sve)
Thank you for that report - I think that I have found a fix to this, which I have pushed to the 10.x branch on Github.
thanks james!