MAJOR E licenser dongle problems cubase 9

Having massive problems ! anyone else experiencing this
I have the latest version of cubase 9 installed and the latest version of e licenser
working on a desktop mac pro 10.9.4
when i boot my machine e licenser can see my dongle with my authorisations i can do maintenance all ok, when i load cubase up i get message runtime ‘DLL connection to protection device’ , and then ‘no valid license,’ and then when i check on e license the dongles are gone !
i thought this was because of my old dongle which was what tech help advised was probably the issue, the new dongle has arrived i have successfully transferred licenses across and the machine reads it fine , then the same problem when i load cubase ??? and now when i have checked my products on mysteinberg my cubase 9 update isn’t showing !!!
i have lost nearly two weeks of work now my deadline is approaching.
the system is a new machine and worked fine for a week ? then it all went very wrong!
I am going to phone tech help first thing but any ideas would be appreciated
thanks Olly

Solution i upgraded OS to high sierra and i am in !!!