Mounir IDRASSI - 2020-07-04

Thank you Frédéric for this report.
This issue is strange. One possibility is that VeraCrypt is blocked in the step where it tries to associate the mounted volume with a drive letter because of some unknow issue related to Windows Mount Manager.

Since there are no logs or debug trace in VeraCrypt, on order to try to know more about this, can you please try to mount the disk on the affect machine using the mount option "Only create virtual device without mounting on selected drive letter" (this option is available when you click "Mount options" in the password dialog)?
If VeraCrypt is able to mount quickly, then my hypothesis is correct and there is an issue in the Windows Mount Manager.
On the other hand it is also blocked, then the problem is at much earlier step, for example while VeraCrypt tries to read the volume header.

Anyway, let's see you test result first. Thank you.