Hiya,
If you can log on to:
http://<your adfs url>/adfs/ls/idpinitiatedsignon.aspx
If not:
1: The site is disabled for improved security, you can enable it for test purpose.
2: Your ADFS is not working as expected.
If that site is working, your ADFS server is working and the problem usually lies within either:
A: The relying party, you have set it up, as defined by your application vendor. Error is usually in Certificate, Claims type definition.
B: FederationMetadata mismatch. If the federated metadata is not exchanged automatically, but manually this can be prone to errors.
Remember to check your ADFS log, not always the best, but it usually gives a general direction.