Previously my project was in another machine. Then I added project into my new machine. After that I got error "error could not find or load main class". Then I remove JRE system library and again add. After that remove unused jar files and save the java build path. After that previous error removed and all code work finely. But every packages and classes from the beginning it shows yellow color exclamation mark. Doesn't give any error message. What is reason for that? How I remove it? Not red color. That's yellow color. (This happened to previously exist classes and packages. Not for newly creates classes)
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