I just updated a fresh staging copy with Meta Box AIO 2.8.3 to have AIO v3.2 and still got the error reported.
This is really annoying as I set up three weeks ago a staging copy for Peter of Metabox to do the upgrade and see the error and I've received no response from him as to whether he did upgrade and determined what the issue is.
Come on Meta Box, this issue is now causing quite a few of us an issue and we can't upgrade. I would have expected this to have been resolved by now.