If you are running SAP B1 9.1 and an older version of B1UP (lower than 2014.12 HF1) you might get this error message:
This error is due to SAP's new Hide function feature
The way SAP has implemented this feature is a bit unlucky in that "hide" means taking menu-items away that add-ons expect are there and hence the error.
Once the B1UP team realized this we implemented a fix for this so if you are running B1UP 2014.12 HF1 or higher you should not be affected (http://www.boyum-it.com/sbo)
Should you not be able to upgrade then removing the hide checkboxes from the General setting will also make the error go away.