7.X XenApp/XenDesktop VDA's Become Unresponsive (Hang) Intermittently Or Blue Screen (BSOD) with Bugcheck 0x00000022.

The issue has been reported for 7.15 LTSR CU1, 7.16 as well along with other old versions like 7.8, 7.14.

The issue is addressed under LC8749 and is now included 7.15 LTSR CU2 .

https://docs.citrix.com/en-us/xenapp-and-xendesktop/7-15-ltsr/whats-new/cumulative-update-2/fixed-issues.html
VDAs might experience a fatal exception on picadm.sys and display a blue screen with bugcheck code 0x22. [#LC8749]

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Problem Cause

From the complete memory dump if was found that an excessive number of threads were blocked by PICADM.SYS. There was a deadlock with the writelock and readlock within PICADM.sys which caused the kernel to enter infinite loop. 

On Further dump analysis it was found that this issue was caused due to corrupted directory entry list . The directory entry (and  its corresponding  directory node) was freed and was not removed from the entry list, which caused the inconsistency in the structure of the directory entry list and caused  BSOD or infinite loop depending on how the freed directory entry was used later. 

7.X XenApp/XenDesktop VDA's Become Unresponsive Intermittently Or Blue Screen (BSOD) with Bugcheck 0x00000022