Ok, I posted under "other" with my RX8 problem, but I just now found that there was a web page updated on Sept 16 2025 that states iZotope is not compatible with Tahoe. Would have been nice if they'd emailed all the folks that have had some recent activity with registration/updates…
https://support.izotope.com/hc/en-us/articles/30376914183965-macOS-26-Tahoe-Compatibility-Statement