I have installed the latest rig manager version and using .net framework 4.8 (that is a windows feature and not a different app from 4.5 version)
I think that the point that is a windows issue can be certain but it is caused by an incompatibility of the Rig manager with the .Net version as the problem window asks for a 4.03139(or something as that) specific version
The point of asking is that Kemper send me here for solving the problem, but it is not a problem that anyone at the forum faced before and I was waiting that someone faced it and solved that and how did it.
Anyway the problem has been send to Kemper again.
Thanks for commenting