QGIS: OGR error when editing Geopackage layers : database is locked

ok unfortunately I performed 2 different resolution activities, and im not sure which activity resolved the problem.

First Action - I had previously run a python script (outside of QGIS) which had completed, but it had used the Geopackage (a different table though). I simply closed this python console window (maybe the console or process that ran inside the console had locked the DB?)

Second action - In QGIS, i went to Database > DB Manager and 'Reconnected' the database. I then reloaded the layer inside of my QGIS session, made an edit and saved. all good.

So - whether it was the first or second action. not sure.

In QGIS open your layers, then in database manager make a connection with the geopackage, delete all the layers, it is going to be opened in your actual project, then export each one to the same geopackage, it's going to appear the new layer with another style, so I recommend you to save each style too. It works for me.

When you open a geopackage, a few hidden extra file appear next to it in the directory. That basically lock the file so that no other user can change it. While geopackage is a database, its limited to one user. In this case Python had a handle on the file. If python crashes, it can sometimes keep the handle on the file until you kill the process.