Okay! Looks like yours is newer than mine.... so I will tell you what you can do temporarily. Open the .xml file up in notepad..... Find the row that has the blank pricevaliduntil field and then copy it..... Ctrl-H and paste it in the "find what" paste it again into the replace with and in that section put a valid date that google will accept. Then replace all and save.... Let me know if this helps.