So I've seen this error is rather common, however most responses relate to Eclipse. I am using Intellij IDEA and getting the same error. This error is a little different than others in that it specifies not only the java test file, but the package as well. Other errors I've seen did not mention the package in the error.
So far I have tried: 1. Set CLASSPATH=%Path to dependancy module1%;%Path to dependancy module2%;%Path to SeleniumServer jar%;%Path to code libraries%;%Path to TestNG jar%;%Path to XML file%, etc... 2. Invalidating and rebuilding cache in IDEA. 3. Verifying that the package is actually specified in the XML file.
Extra info: I am not using Maven, or I would just use that for the scheduled runs I'm going for. IDEA Community 15.0.6. TestNG 6.8.8.