As integration was developed based on older version, I suggest you to test if it works with 3CX Phone System version 15.5.
Also, you could ask other partners. Might be they have customers using this version.
Hello,
We also have a customer on windows who is on 2026-02-28 having the exact same error message after updating.
The title of the messagebox is in our case is: "C:\Program Files(x86)\Han...
