When linking a Payment to a Deposit, the GL account is incorrect. The following error can also be returned since the account is generated incorrectly: Error: Data could not be saved. In account system "<account system name>", the account "<account number>" does not exist. The action could not be completed.
Download and install the latest patch, which contains all fixes from previous patches. If you are running an older version, download and install the latest version and then the patch.