Hello,
Hmm...this could be a few different things:
First, make sure you are only logged into one Google account (very important) and that this folder with the doc files is on your drive (not a team or shared drive), and try again while in a Chrome Incognito window
Next, when you are at step1 to select the folder and the window shows up to search, just click on your folder once to select, do not double-click into it.
If you still get the spinning wheel, can you please hold down Control+Shift+J" on a PC or "Command+Option+I" on a Mac and when the side window opens, take a screenshot of the error console ( make sure the side window is on the 'console' tab)Thanks!