If I exit LR after exporting edited images without clicking reset then when I return to LR is appears that there is no way to undo changes to start a new edit and I am stuck with the edited version. is there a setting so that the original RAW file will be available in my catalogue, or even both edited and uneditted versions ? I export as JPG to an external drive and am using latest updated version of LR classic in Windows 10
In Lightroom every step developing a picture is non destructive. It means you can go back every time to the original RAW file. There's a setting in the export options that a exported picture was added to the catalog, so you'll have both.
I've never heard about such a issue.
In a first step I would try to reset the Lightroom preferences.