Your comments

Since unplugging the C1 connector and plugging it back in resolved the issue, it is probable that there was something in the connector that altered the restance that the MD4 measured on the IdTag. Perhaps if they have applied some grease in the connector.
The message "Wrong IdTag" is given both if you have an IdTag with the wrong number (e.g. a 2 instead of a 1), but also when there is an invalid resistance that does not match the range for any of the IdTags.

For the MD4, power cycling the module (cutting the supply to the +BAT pin) has the exact same effect as unplugging the connector and plugging it back in. It will reboot, and at startup it will read the IdTag.
No, the delay must be on the activation of the XC10 DOUT:s, so if there is a delay in enabling the XC10, then the DOUT activation comes at least one cycle after the module enable.
The output delays (IDC) does not get processed by the XC10, the XC10 only sees the DOUT:s as its commands.

Yes, if you do not have any delay in activating the XC10 via the Enable property, then you can activate the DOUT as soon as the IQAN master starts, and the XC10 will activates its outputs without the need for a flank.

That is strange.
The module only reads its IdTag during start-up, so if this is happening during operation, that seems to indicate that something, e.g. a glitch in the power supply, is causing the MD4 to restart.

Are you sure the report about it occurring during machine operation and not during machine start is correct?

The most probable wiring fault for the IdTag would be an open circuit, but for that fault you would get a different error message, that would instead say "Safe mode! Application not loaded".

One guess, that is really just a guess, is that perhaps there could be an issue with a really low supply voltage. This is not something I have ever seen, but since the IdTag is using a 5V reference to measure the IdTag resistance, a supply <5V could perphaps in theory cause an incorrect measurement. But I have never seen this happening, it is just a thought.
Currently this is not possible, for performance reasons the MD4 video control is writing directly on the display regardless of other layers.
Yes, this problem is triggered if these DOUT:s are activated at exactly the same time as the XC10 is enabled, The workaround is to extend the delay-on time for the DOUT:s, it should not have to be as long as you have set it now. In the example application for the workaround, I have put it to 100 ms after enabling the XC10, and that works.

We are just about to release an XC10 firmware update to support DOUT diagnostics features in combination with IQANdesign 3.15 and later. But this update we are releasing now does not resolve the problem of DOUT:s requiring flank after module enable.
I am not sure that I understood which method you used, but there are basically two ways for bringing up a display page.

The method I use the most is that I set an action on a button, where the action is to go to the page you want to navigate to. Like this:

The other method is to use the Show property on the display page. That way you can control the showing of the page from you application. The last display page to see a change from false to true on its "Show" property will be displayed.

Hi Kevin,
Do you use the Enable property on the XC10?
Normally all IQAN IO are level triggered, but we have a problem in the XC10 firmware has the behavior that some of its DOUT:s will need a flank after module disable. It is the DOUT:s that are also combined as XC10 PWM:s that have this behaviour. Here is an example of how to make a workaround for it, I only used 100 ms after the XC10 enable for delaying the DOUT.
XC10 DOUT workaround.ids3

The issue above should not exist for the XA2, but there is another possible explanation for the problem you experienced.
If there is a fault that affects outputs, the behavior is that these outputs will remain off with the error status until the error has gone away and there is a zero command to the outputs.
The purpose of this is to avoid unexpected restart for outputs that are controlling machine movement, if the error is intermittent.
This functionality is controlled by the master module, and in IQANdesign you would see the error status and that the DOUT has the value false.
If you want a function that automatically restarts the DOUT after an error, you can achieve this by blocking it when there is a fault.

The font selection is today mainly used for supporting languages with non-latin characters, e.g. Chinese.

One workaround for the example you mentioned where the unit "°C" is a static text could be to bring that in as an image instead of a value control or text control, and use the font that is set for the selected language only for the value controls on the display page.