I think by server-specific keys you mean the encryption key that is in later versions of Sage 100 and can cause issues if you try to copy in a MAS_XXX that was not originally migrated to the test site?
The way I do this:
1. Migrate to new Sage 100
2. Setup/convert data in the new Sage 100
3. Upon final go-live copy/paste MAS_XXX from old ( which is the copy I migrated from ) to new
Where I think you can run into trouble is if you try to copy/paste a MAS_XXX from a system that was not the one you migrated to the new Sage 100
In those cases, I think people get around it by manually copy/paste the encryption key into SY_Company however your mileage may vary on whether this works with payroll.
I don't ever try to copy/paste a MAS_XXX into a new Sage 100 if that MAS_XX wasn't part of the original migration so I can't tell you for sure what workarounds may or may not exist to make it work ( aside from thinking copying the encryption key might ).
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Wayne Schulz
Schulz Consulting
860-516-8990
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