We show error plaques quite a bit in our games. For example, in our medical 'games' a patient ID bracelet (ID QR code) must be scanned before scanning a medication (Med QR code). In a real hospital the patient ID is always electronically confirmed before electronically scanning the medication to be given. We create a player attribute called 'ID verified' and set it to be '1' when the patient ID is scanned.
2 plaques are ready for when the patient medication is scanned, the error message plaque is triggered when 'ID verified' is 0, and the medication information plaque is triggered when the 'ID verified' is 1.
An additional wrinkle that we implement is that we have a timer event set this attribute to zero after 2 minutes. This replicates the real hospital process for verifying patient IDs. It must be re-verified when time passes.
So we really never allow the ARIS default error message to show if possible. But it will show if a code is scanned that is not built in to the game, of course. We try to catch as many error conditions as possible and create custom plaques to show/guide the user when they occur. It can cause a lot of scene bloat though.
One feature that would be nice is if you could list more than one QR code for a specified error plaque.
For example, as in the situation above, there could be 10 possible medications that a patient could get in a certain situation. If the patient ID has not been scanned yet, we want a certain error plaque to show when any of those medications are scanned prematurely. Right now we have to place that error plaque in the scene 10 times, once for each med code with the trigger situation mentioned above. It would be nice if we could enter all 10 medication codes, separated with a delimiter into the trigger for 1 error plaque.
I realize that the more QR codes are available, this becomes onerous. The scene structure does help control the bloat for us as we can separate things into patient/scene states within the scenario.