adham,
It’s possible that your installation is corrupt in a way that isn’t being fixed by re-install attempts. Please follow these steps:
1) Shut down Eclipse
2) Download this utility JAR.
3) If you have installed your Eclipse instance via a ZIP/tar.gz file, please place the JAR in the Eclipse directory. If you’ve used the Eclipse installers to install Eclipse, you can place the JAR anywhere.
4) Open the command prompt, and from the directory containing the JAR, run java -jar VerifyCodeMixIntegrity-1.0.jar
.
5) If this detects a corrupt installation, it will clean the installation, and prompt you to uninstall and re-install CodeMix now.
6) You can now start Eclipse and attempt to install CodeMix again (there’s no need to uninstall it as the tool suggests).
Please let us know if this helps you resolve your issues.