A customer reported that a custom application did not respond correctly when resizing the Window. The Window flickers and changes the Window position.
The customer changed the global seamless flag to 3EFFB6 which is all values combined. The issue did not occur.
To tweak the behavior of the application within the seamless Citrix session, a number of seamless flags are available. However, sometimes it is difficult to know if these flags can resolve the problem.
You need access to the registry on a test XenApp server to test these seamless flags.
Caution! This procedure requires you to edit the registry. Using Registry Editor incorrectly can cause serious problems that might require you to reinstall your operating system. Citrix cannot guarantee that problems resulting from the incorrect use of the Registry Editor can be solved. Use the Registry Editor at your own risk. Back up the registry before you edit it.
To identify the specific value that can solve the issue, the Technical Support Engineers requested the customer to change the value of the seamless flag using the following registry value on the XenApp server, before each new session. The engineers also requested the customer to remove the values one by one.
Note: Refer to CTX101644 - Seamless Configuration Settings for more information about the values for the seamless flags.
Registry Key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Citrix\wfshell\TWI
Value Name: SeamlessFlags
Value Type: REG_DWORD
Eventually the combined value 3B6 also did not resolve the issue.
The engineers then requested the customer to use the following seamless flag:
FORCE RAW MOUSE EVENTS TO SERVER
This resolved the issue.