Question about modifying a current existing route.

[jonpd]

I stand corrected. (well sit anyway...) It's just that on a few occasions I added missing buffers to some sidings on TS Mullan route and then got an error message when I tried to restart the saved activity. This ONLY happened when I added the buffer stops to existing sidings. However I can add hazards (deer crows etc) and then restart a saved activity.

A buffer is just another kind of track section. Any track changes will break a path that uses it which in turn will break the activity.
In some cases you might be able to repair the paths in ORTS track viewer using the "auto fix all broken paths" function.

Jon

[eolesen]

There's a hack for tricking a small TDB change to let an activity resume... change the TDB and RDB serial number. It increments with each modification. If you know what the activity saved, you can try rolling that number back manually....

[niknak]

Thanks for the responses guys.