Sometimes when you try to open Quantities Report you get "Quantities Report by Named Boundary".  This happens when there is a corruption in a temp file.  Please follow steps shown below to resolve the issue:

• Exit all OBM files you have open on the machine
• Open File Explorer and navigate to “C:\Users\user.name\AppData\Local\Bentley\OpenBridgeModeler\10.0.0_1\prefs\civil_commands”
• In the folder delete “REP Report Quantities.xml” file
• Open OBM again and try to generate the Quantity Report again.
• In some cases you may have to reboot the machine.