I was getting the error “Citrix XenApp cannot contact the license server”. this error was caused due to service failed on Citrix license server. The License service was up for a minute and failing iimediately.
Solution: Delete two files “concurrent_state.xml and/or the activation_state.xml” from
C:\Program Files\Citrix\Licensing\ls\conf\activation_state.xml and concurrent_state.xml on a 32-bit server
C:\Program Files(x86)\Citrix\Licensing\ls\conf\activation_state.xml and concurrent_state.xml on a 64-bit server
/opt/citrix/licensing/LS/conf/activation_state.xml and concurrent_state.xml for License Server VPX
Now restart teh Citrix license service on license server.
he solution was to rename “concurrent_state.xml” and “activation_state.xml” to “concurrent_state.old” and “activation_state.old” respectively and restart Citrix Licensing service. You may also need to restart Citrix Licensing Service, Citrix Licensing Support Service and Citrix Licensing WMI services.
cd “C:\Program Files (x86)\Citrix\Licensing\LS\conf”
rename concurrent_state.xml concurrent_state.%TStamp%.xml
rename activation_state.xml activation_state.%TStamp%.xml
net stop CitrixLicensingConfigService
net start CitrixLicensingConfigService
net stop “Citrix Licensing”
net start “Citrix Licensing”