What do these colours mean?

Hi all,
If I connect our simulator PMU device (MSV1) to openPDC; it works, but the highlighted text fluctuates between red and green. I have attached a screenshot when the text is red. Also the status light next to the device name is yellow instead of its usual green. What does the red and yellow mean?
It’s only recently started doing this, and I haven’t changed anything at the PMU side.

Last time when i had this issue it was when the device lost the time sync. You may want to double check the time sync is correct on your PMU. Hope that helps.

Thanks Rex, I’ll check that out.