Sorry to hear that you’re having problems with UltraReverb in Ableton.
-Are you using the AU or VST version of UltraReverb?
-What directory is the plug-in located in?
-Can you send us/post here the crash report so we can see what is happening?
We can get you an older version of UltraReverb in the meantime. Send an email to email@example.com mentioning your issue and my name, and I can send you an older version.
i’ve reasearched further and it seem that 2.0.17 IS stable in Ableton 9.5. However 2.0.11 did seems to throw an error in Ableton but so did Max For Live, and the crash that I got after updating Ultrareverb to 2.0.17 came from Max For Live and not Ultrareverb, so all is good.
Thanks for you help and sorry for the alarm!