I assume you've managed some nodes, and maybe created some custom views.
Check the status of the imc processes either in imc under System > Server Info or log into the imc server and run the HPE intelligent deployment monitor and look on the process tab. imcl2topodm.exe is a likely suspect as I recall.
In the deployment monitor you can right click on a process and restart it. if it won't start or if all processes are running then you will need to check the logs. They are in <Install Vol>:\Program Files\iMC\server\conf\log if you installed on Windows