In all of my sites that I use WPvivid on I experience a strange bhavior recently:
There is a file created in the root of any site that looks like a rest of your tests:
“F:\wamp64_3.19\www\wordpress\test_premium\wp-content\wpvividbackups\test.txt”
What’s that? It just contains “test2”.
I have not created that file nor is that a path on my server. Seems you are testing a premium version?