Symantec Endpoint Protection Error analyzer/processor submits data to Broadcom Symantec for analysis regarding process crashes. Symerr.exe process is conducting a ipconfig /flushdns to help remedy network connection issue as part of a self heal feature of SymQual. This feature tries to rectify any network related errors. One of the steps is to release the IP address via iphlpapi calls. This release and renew of the IP address results in the Citrix connection drop.
Symantec is currently investigating this issue. This KB will be updated when a fix or more information is available.