Critical issue should not be open here in the user forums.
Please open a support case to get help with this issue
The data_engine being down will be the cause of your issue.
you can try setting the data_engine loglevel to 3 and logsize to 75000 and restart the robot and see what you get
the other thing to check would be that the distsrv is running and not having problems as the data_engine checks
this to when starting up. If it can not get the licence from the distsrv it will not start,