When you view a report with barcode UFL functions through Crystal Report Viewer ActiveX, an error message box pops up with text The Visual Basic UFL that implements this function is missing(or U2LCOM.dll is missing).

When this error message happens, either the Crystal Reports UFL is not installed on the target computer, or u2lcom.dll is missing. u2lcom.dll is required for all COM-based UFLs. This dll is not installed by default when Crystal Reports ActiveX is installed. This dll is not a COM dll therefore does not require registration. However, it must reside under the same directory as Crystal Report Engine DLL, crpe32.dll, or under Windows system directory.

First make sure you have the barcode UFL copied and registered on the target machine.

In the target machine, search crpe32.dll under directory C:\Program Files\Common Files\Crystal Decisions. This directory contains all the Crystal Reports runtime. Copy u2lcom.dll from the developer machine to that folder. Restart Crystal Reports Viewer.