Failed to download file when opening - restart helps

[technofrikusEBZ24]

Hello,

when opening a design inside Fusion 360 on a Mac (latest Catalina), I get the error "Failed to download file". (btw: why are error messages visible for literally 1 second before disappearing?).

There are no TABs in the file names. Maybe some have special characters like ü, ä, ß etc, but I am not sure if all of them have (just thought about checking just now). When I restart Fusion (not the computer) it works again.

I had this problem for months, but only very occasionally. Recently it seems to get worse. That is why I am posting.

Edit: I just had another file with that error message. It has two "ü" in the filename. I replaced one "ü" in the filename with a "u" and it still didnt open. Then I replaced the second one and it opened, without restarting Fusion. Changing spaces to underscores didnt change anything. To I guess this is a special character problem.