A required resource was
I get this unfinished sentence "A required resource was" in a message box when I click on the Devices tab, and have to click OK a number of times to clear it.
When it clears there are 25727 slots in the tape library (Overland LTO with 10 slots).
Sometimes the whole screen goes completly grey and the only way to get icons back is to move the mouse around clicking at the same time and the icons reappear.
I have some screen grabs of these conditions but am unable to grab the grey screen.
What does the message mean, why is it appearing and why do I get so many slots in the library??