This occurs when you do not have sufficient permissions to the folder that BankLink Books is installed to. To rectify this log in with a profile that has sufficient read/write permissions to the BK5 folder or alternatively alter the permissions on the active profile so that there is read/write access to the BK5 folder.
BankLink Books needs to edit and change particular files in the BK5 folder in order for the software to function. In order to achieve this, you need full permissions to the BK5 folder otherwise when the software attempts to update a file with a newer version it is not able to and produces this error.
To resolve this problem contact your local IT department or external IT technician to change the permissions to your user profile to allow you to make changes to the BK5 folder.
This is a permissions issue due to incorrect settings on the Windows user profile which needs to be addressed by your IT consultant/department.