Sorry for late response.

If the incomplete folder with files still shows in the Library window, select that folder, click the arrow next to it so it opens, then select all the files whilst holding down the shift key, then press Resume button. This will force all incomplete files back into the download window. They will initially show zero % but once started downloading again their previous % will show.

If the previous incompletes don't show in the incomplete folder, then go to LW's preference settings, first option (Saving) will show present selected download location, change it back to previous location using the Browse button.

But before you do, make a backup of your download.dat.bak files from the older incomplete folder just in case. If it does't recognise the previous incompletes, then close LW, replace those files with the backed up ones & restart LW.