I have the same issue. I found a lot of this in the ems.log:
ERROR [Thread-93] com.intruvert.ruleEngine.profile.filter.definitions.update.SensorUpdateRequestI tem - Error updating sensor: 1001
java.lang.RuntimeException: CompilationError Compilation Failed
I need help too
I opened a case with McAfee, they told me that my versions of NSM and the sensor software didn't support the signatures that I was trying to update.
You need to log in to McAfee Service Portal to acces this url https://kc.mcafee.com/agent/index?page=content&id=KB87554&actp=null&viewlocale=e n_US&showDraft=false&platinum_status=false&locale=en_US
So, I updated both the NSM and the sensor software and everything is working now. You can update the software trough the NSM, but you need to update the NSM first and before you start the updating process you need to back up some important things.
How to back up and restore the configuration tables on the Network Security Manager
How to back up or archive the Network Security Manager database, tables, and UDS
Updating proccess, starts in page 115