Does your bundle import that package where the xslt file reside?
I am having the same issue.
I am using an XSLT in the same bundle as the route definition.
I have tried putting the XSLT in a normal package as well as the default package (src/main/resources).
Is there something that needs to be done to get Blueprint to work with the xslt URI?
This is fixed in camel 2.8