Known Issue added to README - Enable Preview Maven bug (#270)

* Known Issue added to README - Enable Preview Maven bug

* Update README.md

* Update README.md

Author: subhash-arabhi

README.md

@@ -189,6 +189,11 @@ If your extension is not starting and throwing some error like no JDK found even
 ## Workspace
 The extension will analyze the content of the opened workspace, and relevant other files. If the workspace contains a lot of data, this may take a long time. It is therefore recommended to avoid adding unnecessarily big folders in a workspace. Specifically, it is not recommended to open user's home directory as a part of the workspace.
 
+## Known Issue
+If an action has been applied to the Maven `pom.xml` file through the extension, such as enabling a preview feature or adding a test runner framework, subsequent compile or run operations may fail. To resolve this issue, please follow the steps below:
+1. Check the `pom.xml` file for any duplicated tags.
+2. If duplicated tags are found, remove the extra tags and attempt to compile again.
+
 ## Contributing
 
 This project welcomes contributions from the community. Before submitting a pull request, please [review our contribution guide](./CONTRIBUTING.md)