I also currently have a few of these:
E0316 06:28:51.040291 19 log.go:32] Unable to read: Key: [0 0 12 106 98 45 104 117 110 116 46 110 97 109 101 2 10 45 112 111], Version : 90863807, meta: 70, userMeta: 8 Error: file with ID: 1966 not found
which is a error I had reported with this issue in december of last year on the RC of v20.11