After upgrading to SAP Business One 9.3 you find the Add-ins option is no longer available in Crystal Reports (CR) designer. The Add-ins option is missing from the toolbar.
1. Close CR designer.
2. Locate the command Prompt → run as Administrator.
3. Run the following command:
cd “C:\Program Files (x86)\SAP BusinessObjects\SAP BusinessObjects Enterprise XI 4.0\win32_x86\”
4. Run the following command:
crreg.exe DotNetExternalCommandAdapter.dll -gac -regasm
SAP Note : https://launchpad.support.sap.com/#/notes/2655011