You're not alone. Exact same issue here of not being able to select encoders, with the same error messages. Also no sound coming out when selecting Speakers device, only SPDIF-Out works through TosLink.

More details here:
Sound Blaster Z Driver for latest Windows 1903 Update : SoundBlasterOfficial
Creative Sound Blaster Zx driver in 1903? : SoundBlasterOfficial

Creative don't seem to be in an hurry to address the issue. If they ever will. And I'm not wasting my time with MS's "support", they're too robotic, and threat you as IT noobs with their boring step by step process that fix nothing, and that most people already did anyway. I think I re-installed the drivers over 10 times.

Using various methods/approaches. Driver cleaner, safe mode, un-installing all other sound drivers from other devices, etc. Always the same.