Thank you for your post.
I am unable to replicate the problem on my iPod touch running iOS 5 and FileMaker Go 1.2.3. Here are the steps I took.
1. In FileMaker Pro 11.0v4, I created a database file with one field.
2. In the Layout, I created a Web Viewer that displays our company address (5201 Patrick Henry Drive, Santa Clara, CA 95054) in Google Maps.
3. I created a script that uses Open URL and specifies the same address in Google Maps.
4. As a hosted file on the Mac, I accessed the file via FileMaker Go on the iPod touch. The Web Viewer does display the Map after a few seconds.
5. I performed the script, and Open URL loads faster and shows the same address.
6. At the bottom of the display, I tap "Open in Safari". Safari is launched and the address is displayed.
7. I then double-tapped the home button, and switched back to FileMaker Go, and the information displays in the Web Viewer. No crashing.
If you are not returning to FileMaker Go properly, make sure you have extended privileges and the keyword fmrestorelogin (lowercase) defined for those privileges. This privilege allows users to resume an interrupted FileMaker Go session without being asked to authenticate again. You can read more about this in the FileMaker Go Development Guide at:
... or the FileMaker Go Technical Brief at:
Let me know what I'm doing differently than you so I can replicate the problem.