I am switching HDs for my syncthing destination drive.
But, after copying my new folder information exactly while changing the destination drive, syncthing does not allow me to save the new folder set up. When moving the mouse over the save button, I get a circle with a bar through it, and saving is not possible.
Are you using the same folder ID? Each folder ID can only be used once per Syncthing instance, e.g. you cannot sync two copies of the data on the same machine running Syncthing.
Looks like it thinks there’s a validation error on the folder ID, and also that there’s some confusion. You can’t really tell from just looking at the screenshot, but the explanatory text under the folder ID is a jumble of both “normal” descriptive text (“Required identifier for the folder”) and validation error (“must be unique”). That shouldn’t happen, and the folder ID is presumably unique as it’s trying to add it, so I’m thinking there’s something odd here with the browser or the scripts.
Disable plugins; try another browser; check the browser console.