The Eclipse project has a red exclamation point solution

Why is there a red exclamation mark in Eclipse project

[Problem cause] : The packet path pointed to in classpath is wrong in the project

[Solution] : Right click project name BuildPath -- > Configure Build Paht... , and then several tabs above find the package with the Red Cross in Libraries to be the package with the wrong path. Go to classpath and modify the current path of the corresponding package. Then go back to THE F5 refresh project in eclipse.

The following two paragraphs are for reference materials I found on the Internet when solving this problem:

When you create a new web project with myeclipse, a.classpath profile will be generated in the project directory, containing the jar configuration referenced in your project. This.ES27en has no effect on your web project, it is actually identified for myeclipse. This is because the configuration in the.classpath file refers to an jar, but in fact your lib does not have this jar so there is a red prompt.

You don't have to take the.classpath file and look for your jar1. You now open MyEclipse and right-click your web project to find Build Path > Configure Build Paht... > Then there are several tabs above to find Libraries. Here you see all the jar references in your project. Is there a small yellow exclamation point on one of the jar ICONS?

If so, select jar and click Remove to the right > Click OK and wait for a few seconds. Now the red XX on web project is gone.

Explanation 1: The yellow exclamation mark of jar indicates that the classpath configuration file references jar, but jar is not actually in lib.