That is strange.
Do you have DEP (Data Execution Pervention) activated?
If so, try to disable it, or add Regsupreme Pro to the allow list.
To do so:
1. Control Panel > System
2. Advanced > First Configure button > DEP Tab
3. Now press the add button and select the .exe for RegSupreme.
Now try to run the registry cleaner function again.
Also, check if you have administrator rights.
This can also stop this function from working correctly.