Recently a specific Citrix server in a farm was not accepting any new connections even though login was set to allow and RDP connections were working. A check in the services showed Independaent Management Architecture was not started.

I checked the disks to make sure there were not full.

A look in the event log showed :

“Failed to load plugin C:\Program
Files\Citrix\System32\Citrix\IMA\Subsystems\Ima PsSs.dll with error
IMA_RESULT_FAILURE.”

I found the following article  : http://support.citrix.com/article/CTX129194

A DSmaint recreaterade did not fix the issue

I also had to run dsmaint recreatelhc