Android build error when using Unity Ads

I'm working on an Android game that has Unity ads implemented. Whenever I try to build I get the following error.> Error building Player: Win32Exception:> ApplicationName='javac.exe',> CommandLine='-bootclasspath I'm pretty sure the problem has to do with Unity Ads specifically, because it was building just fine before I was using ads. I've googled this error plenty of times and came up with a lot of answers, none of which helped so far. If you know what the error means or how I can solve it, I'd really appreciate your advice.