Hey,
I just migrated my sonarr v3 database from osx to windows and thought it could be useful to share my experience.
When using the nzbdrone.db from osx to windows, sonarr v3 would not start it’s UI because of invalid paths in the series profiles.
Instead of allowing you to modify that, it just stops you from doing anything.
So you have to manually modify the nzbdrone.db.
For this use DB Browser for SQL lite program.
Open your DB (keep a backup), switch to browse data.
1 - change the root folders table entries to the windows paths you will use.
2 - switch to series table. Export the series table as csv. Open the csv with wordpad and do a search and replace for all the old osx path values, make sure you get all the paths changed to your windows path string.
Save and exit wordpad, switch back do DB Browser. Delete all the entries for the series table. Then import your csv (remember to click first line is table headers checkbox on import dialog).
If everything gets repopulated, you are good for step 2.
3 - change the lastsyncon ( not sure of the exact name anymore) column table values for all your series table.
On osx , the date format comes with a date + time stamp like 22:34:12.385882
Windows sonarr does not like that. So take a recent date and remove the decimals after the timestamp. Copy and paste this value for all your series. Had to do this manually Ctrl+v arrow down, took a couple minutes for 476 entries.
Write the DB in DB Browser lite, close, and launch sonarr on windows, for me this worked flawlessly for my DB to be used on windows.
Didn’t find any help anywhere else on the subject, maybe this will help someone one day.