On February 05 2016 the GECAMed Client Webstart was disturbed in some practices
There might be a connection with the Java 8 Update 73 / 74 that was released on this day, but users who did not made any Java update reported similar problems. By now (18/2/2016) the problem seems to be gone, even if you use the above mentioned Java version.
If you still have trouble starting GECAMed over Java Webstart there is an alternative and definite fix is to avoid Java Webstart altogether, by downloading and installing the GECAMed client locally on all GECAMed client machines.
If you are unable to start GECAMEd on you machine, please follow the instructions on how to download and start the GECAMed Client
A drawback of that method is that GECAMed clients having been installed manually by that method will no longer be updated automatically when the next GECAMed upgrade is put on the server.
The GECAMed Team