It's beta. Beta means it has problems that need reporting. Instead of complaining and quitting, put in a report. This is the only way bugs get fixed...
If you used some rolling stock once that had it, then it's embedded in the name-table and cache. Try running Delete Missing Assets on your session a...
My guts are telling me that part of the issue is the number of channels that are used by Trainz TR/TSxxxxx is probably inadequate to handle the large...