If you have a key file that is not read directly via Explorer, it is simply blocked and there is no possibility of including it in the exceptions unless you deactivate the DLP on the client concerned. Of course, this is a bit of a hassle for companies.
We discovered the problem at Starmoney. A file is created there, without which it is not possible to open Starmoney. Bad if this is then blocked by the DLP.
According to the support, I should then deactivate the DLP and work in Starmoney and then reactivate it, which of course is not practical.