Create a new schedule of type XDC. Select XDC to add to the schedule. The Select button is disabled.
This issue is under investigation.
If you are affected by this issue, then please open a help desk ticket and we can provide a workaround.
This issue is addressed in Build 240 FP6 and InfoBurst 2021.2.
InfoBurst Platform Build 240 FP6 - Release Notes
InfoBurst 2021.2.4 - Release Notes