Restoring TF2 backup fails

[Skeewiff™]

Steps to reproduce the bug:

1) Install game and backup its data
2) Copy backup files to another machine
3) Open Steam and chose restore game data option: it will get stuck around file 2765 and fail to continue

[philipp]

Can you tell me where the "restore game data" option is?
I exported the Serious Sam 3 BFE backup but I cannot import it now on my other machine, because I can't find it.

[Skeewiff™]

Steam > Backup and Restore Games menu