Hi Stefan. This is strange to hear. I’m running Pro Tools 2025.6 with the Speech to Text engine installed on an M2 Mac with Mac OS 15.5 and have no issues running Scaler 3.1.
Have you attempted a clean install of Scaler 3.1, deleting all the files mentioned in the clean install instructions on the known issues forum page?
It would be worth manually deleting the Scaler 3.aaxplugin and Scaler 3Audio.aaxplugin files as well located at Macintosh HD/Library/Application Support/Avid/Audio/Plug-Ins.
Then reinstall Scaler v3.1, then reboot.