[Help needed] Import/Export Tools for OpenCart 1.5.0.x

Thanks for this great extension JNeuhoff.

I can export and open the excel file.

However, after clicking on the "Import" button; (trying to import the same excel file back)..This is what happen:-

1) It automatically logged me out of the OpenCart Administration and
2) immediately linked to my Store Front (http://...../admin/index.php?route=tool/export&token=...) with the message "The page you requested cannot be found!"

My OC version is 1.5.2.1

Can please help with this?