When I try to add or delete port 9997, why do I get the same "Error occurred attempting to remove 9997...Could not find config id for port"?

When I try deleting port 9997, I get the following problem: Error occurred attempting to remove 9997: In handler 'cooked': Could not find config id for port 9997. When I try to add port 9997, I get the following error message: Error occurred attempting to remove 9997: In handler 'cooked': Could not find config id for port 9997. Do you know what could be a problem? I am using Windows.