I confirm the issue you report for the NI plugins you mention. Would you be willing to report back here when you get an answer from Native Instruments?
Actually, you’d be surprised. Most plugin manufacturers understand that there are differences under-the-hood between various DAWs, even of the same company, and are quite familiar with having to make fixes for WaveLab (or Cubase) individually. In my experience, WaveLab tends to enforce VST specifications a bit more strictly than Cubase (although PG could jump in here and correct me) so perhaps there’s something that’s not quite up-to-specification in these NI plugins. Then again, perhaps these are indeed WaveLab bugs.
I just dealt with such an issue with iZotope, and they gladly incorporated a WaveLab-specific fix. Would you mind making the report to NI? I could, but you’ve obviously studied this particular issue a bit more and have logs/crashdumps ready to go.
Confirmed here also, with SuperCharger GT, which I know used to work fine in WaveLab 9 (haven’t used it in a while). Now crashing immediately on starting playback.
Update: also crashing with another NI plugin, Driver. So probably all NI effect plugins?
The ones I tried are both VST 2.4 (only) 64-bit (only, i.e. no 32-bit versions installed), both use 32-bit float internal precision, latest versions of everything, and both work fine in Cubase Pro 9.5.20 but crash instantly in WaveLab 9.5.20 with no crash log.
I think it might be related to how the NI plugins report their internal processing precision; e.g. as a test, I copied the wonderful Grungelizer from the Cubase folder into my WaveLab plugins folder, and it works fine, even though it’s also VST 2.4, 64-bit, 32-bit float. I also have a bunch of iZotope VST3’s using 32-bit float precision, no problems there either.
Apart from Supercharger GT, I don’t use any other NI plugins in WaveLab, and I notice Guitar Rig (which is NI’s Fx “framework”) is also on the default ‘ignore’ list in WaveLab, so I can’t test any further.
Philippe was on it: WL 9.5.20 is the version where 64-bit processing was introduced, so that could be an issue with plugs that played nice before (hence his question in the first reply).
In the release notes of the WaveLab 9.5.30 update I see:
“PAR-3132 VST2 Ambisonics plug-ins now work as expected.”
Perhaps related, but Supercharger GT is now working again, so it would be worth trying your NI plugins again.