The 'Unofficial' Tacx Forum

Not sure if this helps, but https://gotoes.org/strava/ can combine the files after your ride. You can merge multiple files together into one, including trimming any overlap.

I've had this happen to me several times too.

Not a fix for the crashing, but https://gotoes.org/strava/ is a great tool for merging two files which is what I've been doing when this happens.