One of the three following options below typically will resolve this issue.
to change the state by refreshing or by ''Auto Refresh''. Have you tried refreshing the UI by hitting the Refresh (Green arrows / Circle) or by using the ''Auto Refresh''?
The following workaround may be used to restore the hosts to Idle state:
1. Create a timeslot starting now. Reserve the problematic hosts. Save the timeslot,
2. Wait up to a minute until the timeslot becomes ''Open'',
3. From the Calendar screen, right-click the timeslot and choose Abort & Free Timeslot.
Please do the following to reset the ''Host State''.
1. Log Into Performance Center Site Admin
2. Select the ''Lab Management'' Tab
3. Select the ''+'' to expand the Lab Project tables
4. Select the table ''Lab_Hosts''
5. Replace the ''SELECT * FROM LAB_HOSTS'' with the following:
set host_runtime_state = 'Idle'
where host_id = 1006
6. Insure ''host_id'' = the number of the problem host
7. Press the ''SQL EXECUTE'' button
8. Confirm Host State is back to ''idle'', replace the update LAB_HOSTS... with SELECT * FROM LAB_HOSTS
9. Press the ''SQL EXECUTE'' button