I know the PV 550 can support multiple user embedded variables in a multitate display (not just time or date tages, but my own), and I know a PV 900 cannot (barfs with an Error 60 upon booting when I tried). Anyone know if I switched to a PV 1000 (2711-K10C8) I can embed my own tags into the different states of a message display?
Post hoc, propter hoc is just one of the great logical fallacies.
Error 60, aka "Application Barf" is displayed when the PanelView operating firmware does not understand one or more of the objects in a terminal application. Empty text objects caused that error in one edition of firmware, and embedded variables in barcode displays could cause it in another. The 9" screen terminals have been around long enough that there are a handful of bugs that you could run into.
Upgrade your terminal to the latest firmware (4.20 for most models) and I think you'll see the application run correctly. If not, start stripping down your application until you can figure out which screen or which object is causing the crash.