tap.exe: Nothing happens after "Waiting for files to become unlocked..." message when files become unlocked

Environment:

Windows 10, 64-bit

OpenTAP 9.6.4

Steps to reproduce:

1. Have two cmd open in OpenTAP folder
2. In one window start a tap run a dialog testplan (so execution remains ongoing)
3. In the other window do a tap package install OpenTAP - > message will be displayed Waiting for files to become unlocked...
4. End the test run execution in the first window

Actual result:

The files are now unlocked but OpenTAP installation does not continue.

Stopping the installation and running it again works

Expected result:

Once files become unlocked, the installation should continue

Other remarks: