Thanks for reporting. At least for Logic I think this is the same bug as reported here. Toggling the record arm button was also how I got the error to occur. I think if you try the commit before the Audio Workgroup stuff was added, I expect it will run fine?
I’ll add Reaper to my testing as I go. There is a fix in the pipeline but there are other edge cases we have to consider and I now expect that won’t be ready until hopefully early sometime next week 
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