Intellij suddenly throwing ClassNotFoundException

Question

I\'m at a complete loss here. I have a project on an external hard drive called LenseProject. Inside LenseProject, I have .idea, lib, Natives

Answer 1

I know its a bit old post but for me helped by going to Run-->Edit Configurations--> In Application Selected your main code file --> Configuration on the right panel. Checked "Use alternative JRE:" and selecting JDK folder called jre(.../Java/jdk.x.x.x_xx/jre). Apply and OK. I am really new with intelliJ but that solved my problem hope it helps someone.