The main problems are:
1) New provinces
2) Whole world is TI because discovery system was reverted
1# would be very annoying to fix in case of provinces that make no sense as undiscovered (as in France), but is doable if you are willing to spend a lot of time reassigning new provinces properly.
2# might be possible via making sure all provinces in the world are explored by everyone as an approximate solution (viable if save was from late game).
There's of course a lot of missing data other than data, but I think stuff not related to history files will be automatically generated.
As for large file, there are some editors for extremely large files out there but it can even be hard to find them, and they're not very good compared to Notepad++ feature wise.
Overall, I estimate it's far more work than is worth your while. Maybe if you could program a save upgrade tool it would be the exception, as it may be faster than making the changes manually.
1) New provinces
2) Whole world is TI because discovery system was reverted
1# would be very annoying to fix in case of provinces that make no sense as undiscovered (as in France), but is doable if you are willing to spend a lot of time reassigning new provinces properly.
2# might be possible via making sure all provinces in the world are explored by everyone as an approximate solution (viable if save was from late game).
There's of course a lot of missing data other than data, but I think stuff not related to history files will be automatically generated.
As for large file, there are some editors for extremely large files out there but it can even be hard to find them, and they're not very good compared to Notepad++ feature wise.
Overall, I estimate it's far more work than is worth your while. Maybe if you could program a save upgrade tool it would be the exception, as it may be faster than making the changes manually.
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