
Fixing "Publii cannot find your sites folder".
I'm using Pulbii for this site and MrsVark's Wheely Happy Days site.
So that I can use it on multiple devices, I have the "sites folder" saved in my OneDrive account.

However, every now and then when I fire up Publii on a different device to the one I've most recently been using, I get an error message before the app fires up.

This prevents you opening Publii and you can't, therefore, change the setting in app.
I did a quick Qwant search but all of the suggested solution involved changing the location of the Files folder to match the one in the error message then moving it back using the app. And, bejeebus that'd be a faff.
The easier answer is to edit the "app-config.json" file. For my installation on my main PC, this is installed on my OneDrive documents folder. Your mileage may vary, but I guess you're looking for "Publii/config".

Inside that file, you can edit the "sitesLocation" directly.

This has happened to me several times, and each time I've had to search for the solution. But this time, I couldn't find it online and had to dumbly blunder around in the various program files and folders online in order to find the solution. So I'm posting it here as much for my own purposes as for anyone else.