Unable to login on cisco ISE though GUI

we can troubleshoot issue about  Unable to login on ISE though GUI This is very common issue If you are not able to login on ISE thought GUI so in this case you must login ISE via CLI and try to run some command -

we need to stop and start application services use below command 

1- you can verify first all services should running -

# show application status ise

2- If Application service is running then there we need to stop and start application services use below command and before restart you must shift traffic from primary two secondary because its take 10 min to up the devices My suggestion is please do the activity during Maintenance window.

#application stop ise
#application start ise
after run this command issue will fix