When upgrading from any previous version to v1.4.3, tag notes on tags were not transferred to the new database. So if you wrote any notes on tags, these were not transferred to v 1.4.3. This issue was fixed in later versions, so if you upgraded to later version (v1.4.4+) tag notes were transferred successfully.

What to do if this happened to you
When ManicTime upgrades the database it makes a copy of the old database and leaves it in the same folder as the current database. If you did not delete this database, then download this tool

www.manictime.com/setup/custom/TagNotesMigrator.zip

Unpack and run it. It should find the old database and transfer all tag notes to the new database.

If you deleted the backup file, you can transfer the tag notes from any other backup you may have.

Sorry for the problems. Let us know if you need any help.