Ive done it in years past, not this year though.   You can only go 2019 to 2019, you cant transfer a 2018 TT file into 2019 PS.  If you have a 2018 TT file, you have to transfer that into 2018 PS, then transfer the 2018 PS file to 2019 PS. 

Is that what youre doing?

Ohhh, there may be something about it being  a TT Desktop program file, not the Online version of TT...I seem to remember something about that.