The ESEA client is a special case (and there are others like it) that requires interaction with ggLeap and Windows to be authorized to launch due to hacking software, etc.
-In the web admin, go to Settings > Client configuration > Games/Apps.
-Search for "ESEA".
-Click the box art to edit configuration.
a) Enter "C:\Windows\explorer.exe" as Executable Path.
b) Enter the full path under Additional Launch Parameters (It might differ depending on install location).
c) Click "Quicklaunch Menu" if you want this app to be accessible in the client task bar.
d) Select PC group (if you have this feature enabled) where the app can be accessed.
e) Click Save.
-Be sure to enable the app by clicking the toggle in the upper left of the box art. Restart the client PCs in order for the changes to take effect.