Audio drop-out and clock glitches Cubase Pro 10.0.3

Glitches, Drop-outs all over the place:

Create Project
Add Parts
Proceed as normal
Try to start Mixing or just adding to Project

Getting lots of drop-outs and glitches: (Glitch = audio drop out and/or clock synchronization lost).

During Playback/Mixing:
Solo track, unsolo – glitch.
Select Lanes in multi-pass audio track – glitch.
Listen Bus, activate, deactivate – glitch.
Switch track selection during playback (intermittent problem) – glitch.
Enable/Disable EQ bands or Pre filters – glitch.
Enable/Disable many plug-ins stock or 3rd Party – glitch.
Load Plug-in during playback – glitch.

Nearly any function enabled or disabled is causing a glitch in playback and/or the clock to lose its place. Not good.

I tried various audio settings to no avail. I don’t think this is a system malfunction on the DAW or hardware side. All system files and drivers are up to date.

I don’t expect any DAW to load a big sample-based instrument without needing a pause to allow samples to load, but this is worse than in previous Cubase Pro versions I’ve used (Pro 8 updated to Pro 10).

Other reactions:
No restoration of right-click menu; no restoration of the F2 Transport; no fix for the chord track/transpose bug; no side-chain button on the Rack.

In short, none of the the things I dislike about this version of Cubase have been addressed and now the program’s performance seems worse than before.