Fuck Java. Seriously fuck.

Then put the missing class in the services.jar?

@Gatgeagent There is no services.jar and anyway the whole application works, it's just the notification service that doesn't want to understand that the class is there.

"I don't understand the bug but fuck the language anyway"

@tahnik But it doesn't make any sense, how am I supposed to deal with that?

@Artemix But it's there....

@Gianlu If you're using Maven, double check that you made your pom right, and everything is exported fine.

This isn't Java it's googles Android mess

@Artemix @r0bb Well you're right, I should blame Android here

@Gatgeagent I'm using Gradle

@Gianlu If I would knew Gradle, I would totally try to help you, but I only use Maven. :/

Your package naming convention confused me a bit. Sometimes this kind of error occurs when the library on the jar and your project use different versions of the same dependency. Somehow the Dex file gets botched.

Things to watch out for: multiple class loaders potentially having different visibility: unlikely on Android. Provided scope in maven? You said Gradle, idk about Gradle provided dependencies. Different compiled api vs runtime versions? Conflicting transitive dependencies? Imho that's the most likely scenario.

add it to build.gradle
And disable Instant run/hot swap, sometimes it's the problem
and btw thats your fault not Java's or Android's

@Eariel @nickhh @bdhobare The issue was none of those, simply Android was trying to load the class with the system ClassLoader (which cannot load application classes) and that was causing the issue. Not a big if it had not taken me 2 hours...