I am experiencing the exact same issue and error message - have you been able to find a resolution? Thanks.
Actually I found a solution to this - forgot to update this forum..
It looks like a memory issue at the NSM - A McAfee SE told me that values are too low and should always be altered.
I did a modification to the memory settings in TMS.BAT to this (I have a virtual machine with 6 GB RAM):
set JAVA_OPTS=%JAVA_OPTS% -server -Xms2048m -Xmx4096m -Xss512K
You will find it in the forlder where you installed NSM: \Network Security Manager\App\bin
Now everything works 100% - everything is more responsive.
Thanks so much for replying here - it works!!