A "time-out" message may appear if the source code that you've pasted is too large for your system (this is most common in Chrome). It also might happen if you have a weak WIFI signal.
If this happens when importing the report source code, here are some alternate things to try:
(a) Try a different web browser -- or B) 1. Save the source code as a txt or html file
Here's a video to show you how that's done:
2. and then use the option in the import page that says "click here to browse for the file." Here's where to find that.