When the user sees the error 'Access token cannot be null or empty.'
This is an indication that the user needs re-authorize CIA to access the QuickBooks so that accounting data can be posted. The workaround is to click the Blue button labeld '+ Add a Hotel'.
Next, click the 'Get App Now' button., log in, select the corresponding company and Authorize.
The data should post correctly at this point.
If this issue occurs frequently, please report it to CIA by submitting a ticket at firstname.lastname@example.org.