The java.lang.IllegalStateException: Display Not Created Error can be an intimidating and seemingly insurmountable obstacle, especially to a newer Java programmer. Errors like this can be thought of as a roadblock which can halt development progress. Fortunately with the proper know-how, this error can be solved. The following steps will guide you in the right direction to fix this sometime frustrating error.
Symptoms of the Error
The java.lang.IllegalStateException: Display Not Created Error is usually a sign that the file structure of your program does not match the object hierarchy. This is mainly due to issues with the Eclipse windows builder tool, which can sometimes create a platform that is out of sync with the result type. This can cause a rather cryptic error message to show up on the console window:
java.lang.IllegalStateException: Display not created
Steps For Solving the Error
Step 1
The best way to start is to update the org.eclipse.ui.forms plug-in. To do this go to the Help menu and then select Install New Software. From the dialog window that appears, select the What is Already Installed radio button.
Step 2
Once the list of installed software is displayed, locate the org.eclipse.ui.forms plugin and right click to select the Update option.
Step 3
After the plugin has been updated, it is always recommended to restart the Eclipse IDE. This will ensure that all the updated files have been applied.
Step 4
Once the Eclipse IDE is restarted, recreate the same project and see if the error has been resolved.
FAQs about This Error
What does java.lang.IllegalStateException: Display Not Created indicate?
The java.lang.IllegalStateException: Display Not Created Error is an indication that the architecture of your program is out of sync with the result type. This is usually caused by errors with the Eclipse Windows Builder software.
How can I fix java.lang.IllegalStateException: Display Not Created?
The best way to fix the java.lang.IllegalStateException: Display Not Created Error is to first update the org.eclipse.ui.forms plug-in. After updating, restart the Eclipse IDE, and recreate the original project.
What happens if my display has already been created?
If your display has already been created properly, you should not see this error. The error is usually due to a mismatch between the program architecture and the result type created by the Eclipse windows builder.
Are there any other errors that are similar to java.lang.IllegalStateException: Display Not Created?
Yes, some other errors which may cause similar issues include: NoALFormError, InvalidFormError, FormNullError, and FormValidationError.
What should I do if the steps above do not solve the issue?
If the steps above do not solve the error, one should first ensure that the project is properly programmed and the resulting type is correct. One should also discuss the issue with experienced Java developers, as the issue may be due to a more complicated issue.
Further Assistance
For any further assistance with solving this issue, the following resources may be useful: