the? number of rows you can import depends on the amount of content and other factors involved with each row.
My DB upload times out before 500 rows but I have links to Google Maps/Directions in each row that have to be established..
The timeout also logs me out of groups.io.
Mark told us that it's because we are exceeding the amount of contiguous time allotted to each user.
Instead of deleting all of the input you should determine where it quit, clean up the last loaded row and start your upload from that point.
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Bob Bellizzi