GAM Error (_ssl.c:590) help please

[Amanda Cannell]

I have around 250 users to suspend next month and don't want to do it one by one.
So I have carefully followed the instructions to set up GAM and have had it working around a month ago. However now I am getting an error - ERROR: EOF occurred in violation of protocol (_ssl.c:590)

I have completely started again with GAM and set it up from scratch but I'm still getting the error. Its not being blocked at all on the firewall and have tried disabling my anti virus software so now I'm stumped! 

Can anyone help please?

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