I figured out how to make it work. It is some sort of wonky problem with using both programs and a UR44c audio interface.
To make Cubase Pro 11 and Wave Lab Pro 10 work together (with a UR44c), you have to use the Yamaha Steinberg AISO driver for Cubase and the Generic Low Latency ASIO driver for Wavelab. In Wavelab Pro 10 you should ensure that “release driver when application is in background” is deselected (not checked).
I upgraded from Cubase Pro 10 to Cubase Pro 11. When I was using Cubase Pro 10 and Wavelab Pro 10 together I had both program set up to use the Yamaha Steinberg driver for the UR44c, and I had no problems.
What was causing my problem is that when I selected an audio file in Cubase to edit in Wavelab, Wavelab opened and automatically switched from the Yamaha driver to the Generic AISO driver. I had never used the Generic driver in Wavelab and the “release driver when application is in background” was checked and set beforehand. When the driver switched automatically it then caused playback problems in Wavelab and it caused a failure in the UR44c. This failure in the UR44c causes the user interface in Cubase to stop working properly. Once you cycle the power in the UR44c, Cubase goes back to normal.
I wrote about this problem in another post: