Cubase 10.5 has destroyed everything in its path.

Updated from last night.

Mac Mini 2018, Quadcore 3.2gHZ i7, 16GB ram, Mojave 10.14.6

4 out of 5 times, launching a session just hangs the computer. Endless beachball.
Sessions that DO launch spike the CPU up to 300% in Activity Monitor. Not spikes, sustained.
Can not instantiate VST plugins on new sessions. Mouse just flickers over the drop down.
Mackie MCU’s not recognized on startup. Have to turn them off and on, then manually reassign the devices in Studio Setup.

So I figure, fine, I’ll just go back to v10. Except now it’s doing all the same things. Sessions that would maybe put the CPU load at 40% with a 64s buffer are now unplayable. Graphics are redrawing at about 4fps.

This is bad. I’ve been using Cubase since SX3 and have never had an update wreck everything quite like this.
I’m using a decently new, absolutely up-to-the-task computer. No cracked plugins. Clean OS, no other apps on the computer except for a web browser.

Do I have to completely uninstall and reinstall EVERYTHING? Did I seriously pay $60 for this privilege?

Don’t really know. I suspect the answer is yes. I accidentally downloaded/installed C10.5 and it did leave some changes on reversion to 10.0.40. According to my notes, the C10 updates were “HALion Sonic SE, Retrologue & Padshop, Groove Agent SE, and Components”. If you could undo just those areas, that might work. I wonder what “Components” covers? I’m now running 10.0.40 after the accident, without taking any special measures, and it’s OK. But I’m on Win10 here.

What happens when you move the buffer from 64?

Buffer settings didn’t seem to actually affect the CPU lag.

So I’m back in business - here’s what I learned along the way.

First - completely uninstalled both and, down to the nub - including running terminal commands to get old install package receipts and anything else with the steinberg name on it erased.

Second - clean install of Worked ONE time, then on second startup it resumed. I noticed that the MIDI OUT stripe in the transport was pinned. It would take literally five minutes for my Mackie MCU’s to respond to all the volume levels of a session, and they would literally go… one… chan… nel… at… a… time…

Next time I rebooted, my interface wasn’t recognized and it defaulted to the mac’s speakers. But hey, lookie… it’s running fine now.

I re-uninstalled and installed all the drivers and support software for my UR44C. It’s been running fine since. I have to keep the cheesy DSP MixFx software since there’s no hardware pot/switch to turn off direct monitoring.

So apparently somewhere in the upgrade process, my interface’s communication protocols got jammed up and this is what was causing all the headaches. And now I’m reading that the UR44C is not yet supported in 10.5.

Bad on me for not reading all the fine print. Bad on Steinberg for releasing buggy, untested updates that don’t even support their own hardware (and this is a new interface, it’s not like i’m trying to run a 5 year old box over firewire or something!).

I’m not touch the 10.5 update for another few dot one revisions. And I’m making sure I have Time Machine ready to get me out of the woods.

A post script - I am yet to hear back from Yamaberg tech support on these issues. I contacted them Monday. It’s Thursday.

Steinberg, you make it hard to love you sometimes. Not that this is anything new.

Are you using Slate VMR plugin by any chance?