While opening an iLok Cloud Session to authorise Revoice Pro 4 with macOS Mojave 10.14 and higher, this error message could appear:
An exception occurred: Texception: Default
TException.
The license activation process cannot continue at this time.
It is perfectly fine to click "OK"
The activation process did in fact complete successfully.
Just relaunch Revoice Pro 4 and everything will work as expected.