RelFinder needs Adobe Flash to run because it is based on Adobe Flex. If you see this message, you probably don't have Flash installed, which is why RelFinder doesn't run right now. Or you have Flash installed but Javascript disabled, in which case you can start RelFinder manually (or open that URL in a dedicated Flash player).

We configured RelFinder for the SNIK ontology and hosted a copy here, you can find the original one here and use it with your own (or any other) SPARQL endpoint. Due to security and stability issues, we don't recommend you to get flash just for RelFinder, but if you insist, you can get Flash here (take care, there may be adware you need to uncheck).