Dedup.sys 0x7E after inplace upgrade Server 2016 => 19
Solution 1:
In MS Q&A Website there is a notice that this is a know bug and will be fixed in this month's Preview Update (Jul 13) When published it will be under KB5004244 for Server 2019. ref
I hope the reference is not fake as it seems there are a lot of people with the same issue.