The project description file (.project) in the .Java folder contains important information about the project. If the .Java folder is missing, the project will not work properly until this file is restored.
This error occurs when launching Talend Studio. If the error appears, the .Java project cannot be found. It may have been accidentally deleted or moved. The .Java folder is normally created if it does not exist when you start Talend Studio. The following procedure may resolve the problem:
Copy your project from your workspace to some other location as a backup.
Delete the workspace folder or change it to another workspace.