When you say: “attempt to insert any effect”, do you mean also old VST 2 plugins?
Yes, the issue is the same with any plugin selected from the list in the Effects section of the Master Section.
Also, is it the same think when inserting a plugin in a Montage clip?
Yes, I tried setting up a new Audio Montage. I selected a legacy effect and got the same issue.
Can you try to disable the AV momentarily?
I changed the audio device to Windows MME to see if that made any difference. It didn’t. So then I pulled out the PCI-424 card to see if that helped. WL 7 went through a plugin check, then the ASIO multimedia check was done on the Creative Soundblaster card I’m using for MIDI. (It didn’t even occur to me that there might be a conflict between the two cards). After the ASIO sync test, WL came up and I was able to load all types of effects in the master section with no issues.
I then reinstalled the PCI-424 card to see if the issue returned. It didn’t - everything works fine now.
I’m thinking that the issue was user error (of course) because I have a vague recollection of cancelling the ASIO multimedia setup test at one point.
So - no conflicts, issue resolved!
Thanks for all your help!