Hi,
We have a priority ticket system which means that more you will answer to your thread, more time it will take to our team to answer it.
So please, be patient.
I made a little override for your view "backend / isis / product / selectfile.php" so now when you edit a product file, it display the files in the upload safe folder.
That's how I saw that the file you entered for the product "test product" was not right and I guess that there was some extra white caracters at the end of the file (a space or a tabulation, not sure).
Well, I copy the filename from the list and now the test order is working.
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.