Hello jzhang18,
I have an idea why this may be happening. By default, when you first run or debug a program in Visual COBOL for Eclipse, a new "Run Configuration" or "Debug Configuration" is automatically created. This configuration will inherit the Environment settings you've specified inside of Project Properties, but *only if you've set the Project Property for the environment before you first run the program*. Otherwise, you'll need to either:
1) Modify the existing Run or Debug configuration to define the environment variable(s) in the Environment tab
2) Create a new Run or Debug configuration, now that the Project Settings specify the Environment variable. The Environment setting will be automatically added to the new runtime configuration. In this case, you need to be sure to *use* the new configuration when you run or debug your program.
Please see the following link for information about setting environment variables in a Run or Debug configuration:
documentation.microfocus.com/.../GUID-A966EA64-54AF-4963-BE78-75744DB6F9F8.html