I just installed Java 8 on a client machine but when I tried to launch the Designer it froze with the Open/Create Project dialogue partially drawn. This was with Kubuntu 14.04, Java 1.8.0_40 and Ignition 7.6.7.
I then installed Ignition 7.7.4 on another Kubuntu 14.04 machine. The server seems to be happily using Java 8, but the same thing happens when trying to launch the Designer. On both machines when I reverted to using IcedTea (v1.5 using OpenJDK 1.7.0_75) to launch the Designer it worked fine.
It turns out we DO have this in our ticketing system as well. There’s no fix coming from us, just waiting on Oracle, who seems to have deemed Java 9 an appropriate target for the fix