Unable to close a contract

Summary:

Error message when trying to close a contract that incurred some revenue

Content (required):

I keep having an error message when I try to close a contract: You can't close this contract because the revenue amount doesn't equal the billed amount for all project lines on the contract. (OKC-195355).

We are not using billing-invoicing, only revenues in Contract management. Is there anything that can be done to get rid of the error?

P.S I tried to follow the steps from this SR "Cannot close contract because revenue amount does not equal billed amount ( Doc ID 2497220.1 )" but it doesn't seem to solve the issue.