This means there is some error within the code which is in that specific folder or package. Once you clear those errors, it should go away. Is your "myfirstapp" program running when you hit run, or is there an error in the console below? That error corresponds to the red "x" that you are seeing. Once you troubleshoot your errors, the x's on the folders and packages will disappear. If you wan't, you can post the code you are having issues with, or look up the specific error that it is displaying for you and try to resolve it. Best of luck!
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1) Because, In xml file first you have to solve the error. 2) After that clean the project error will automatically get resolved.
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