The Citrix Presentation Server API hooks attach to running processes and load a number of dll modules into the address space of the running application. This can cause problems for some applications which requires disabling the API hooks from attaching to those processes.
Exclude Citrix from attaching to the Symantec Endpoint Protection processes by following the instructions in the following Citrix document. Please ensure you backup the registry before making any changes:
It is recommended, on 64-bit machines, to add the exclusions to the 32-bit and 64-bit registry hives outlined in the document. Exclude the following files, others may be needed as well if you're seeing crashing of other applications or modules: