no main manifest attribute,

It seems like you are encountering a "no main manifest attribute" error. This error typically occurs when trying to run a Java application or JAR file that does not have a valid main class specified in its manifest file.

To resolve this issue, you need to make sure that your manifest file contains the correct Main-Class attribute. This attribute should specify the fully qualified name of the class that contains the main method.

Here's an example of how to specify the Main-Class attribute in a manifest file:

Main-Class: com.example.MainClass

Replace `com.example.MainClass` with the actual fully qualified name of your main class.

After updating the manifest file, you should rebuild your JAR file and try running it again. This should resolve the "no main manifest attribute" error.