I just got this error today after doing some editing. I did some searching and found something about installing Java 8. However checking showed that Java 8 version 71 is already installed. I am using version 5.2 of B4A (and, unless you want to give me a later version, please don't suggest I get the latest). I don't know how relevant this might be, but this is the first time I have compiled something after installing the YouWave android emulator last night.