Resolution:
When reference is a project library, only absolute path works. This might be a path issue for the users who access the same source control project Libraries.

absolute path example : <projectLibEntries path="D:\TIBCO\workspace\BEUserLibrary.projlib" timestamp="1395155980441"/>

Resolution :Use Project library variables instead of absolute path.

Go to your project in BE studio and right click -->properties and go to "build path" and then the project libraries tab. Click on the Add variable tab and try to add a variable name and path to the project library. Restart the studio and perform a project clean and do a refresh onthe project. The project dependencies folder will appear at the bottom of the project with the variables defined.

example :   <projectLibEntries path="FD_PRO_LIB" timestamp="1396304923262" var="true"/>