Hi,
Version 3.5 was released 5 years ago, there have been 59 (!!) updates between the latest release and version 3.5. While I try to maintain transparency between versions, there is unfortunately no capacity to test all the way back with very old releases, I don’t think there is a way to update that to the latest release without any issues.
I think the best possible option in this case is:
– Make sure to have a back-up
– Then Install the new release first
– Then completely wiping all the data via the plugin Maintenance panel
– Then installing the new version again
This will clear any remnants of the old version, and perform a clear installation instead.