I'm using Win10-64 with TB-64 v10.0.5 and the results are the same on two different computers, both containing totally new OS installs. Very frequently when I an replying to or creating a new email, I get a popup every time I press a key that states "A resource is not available at the time of the call, but may become available later" Sometimes it starts working again after a minute or so, but more often I just have to close the editor and start over. I never had this problem with TB v9.3.4 and I can't use TB-64 v10.0.10 because it does not work properly when simultaneously running three instances of TB.