JAR does not exist or is not a normal file:

This error message typically indicates that the JAR file you are trying to access cannot be found in the specified location, or that it is corrupted or damaged. Here are some possible solutions:

1. Check the file path: Verify that the file path you are using to access the JAR file is correct. Make sure that the file name and extension are spelled correctly and that the file is located in the expected directory.

2. Check file permissions: Make sure that you have the necessary permissions to access the JAR file. Check the file permissions to ensure that you have read and execute access.

3. Check for file corruption: If the JAR file is corrupted or damaged, you may need to download it again from a trusted source.

4. Check for file type: Make sure that the file you are trying to access is actually a JAR file. If it is not a JAR file, you will need to use the appropriate program to open it.

5. Check for Java installation: Make sure that you have Java installed on your computer, and that the version of Java you are using is compatible with the JAR file you are trying to access.