Want to do a quick check if you calendar software is able to import iCal files? (All calendar programs should do that. If not, it isn't a (good) calendar software.)
I attach an example file for iCal export here. It contains only a few example files. Of course you can test your own FET timetable with TiTiTo ical export.
The attached file contains 2 types of files. One with BOM and one without. With BOM is "better"/correct, but some programs have problems with BOM. So I also exported without BOM. Try BOM first. If it fails, try without BOM.
You can see the attached example file only if you are logged in as user account in this Forum.
Unzip the file and just import a sample file. (i added activities in that file from year 2014-2019).