Hi everyone,
On the iPad, we support Apple's standard "document provider" API, which allows Hero Lab to retrieve files from various cloud services. Unfortunately, this doesn't work for some users who are using google drive - for other users (including me, and everyone at the company who I've asked to test it) it works fine.
This is a known bug which we're hoping to look into soon - as far as I can tell it's a bug with Apple's APIs (not our software), but I'm hoping to be able to work around it somehow. Sorry for the inconvenience, everyone!