The BIG IP has encountered a problem

Did you make any

Inspect the contents of /var/log/ltm and the catalina (tomcat) log, and try to see what's going on.

less /var/log/ltm
less /var/log/tomcat/catalina.out

Attempt to (re)load the configuration and see if that returns any errors.

tmsh load sys config

Try restarting tomcat, or rebooting the box entirely

bigstart restart tomcat
   (or)
reboot

If that doesn't shed any light, and this is an unconfigured unlicensed box, it may be faster to just redeploy the OVA file and start again.

Alternatively, open a support case with F5 for interactive assistance over a webex session