This is a known defect. It has been resolved in the r3.5 April Monthly Update kit, as well as the GA r3.6 release.
Symptom: The alarm console shows no data and I see a NullPointerException exception in the PCService.log or an error stating the user name and password are incorrect, even though they are a valid OneCick administrator.
Resolution: Fixed an issue where the user name and password entered on the Data source screen may not be properly sent to Spectrum. There is a documented issue that the Data source test button does not test the user name and password. The username/password combination should be verified using a utility such as wget. For example: wget --verbose --user=USERNAME --password=PASSWORD
http://SPECTRUMHOST:PORT/spectrum/restful/landscapes, where USERNAME is the username and PASSWORD is the password that Spectrum was registered with. This should be a OneClick administrative account password.
(3.5.0_Apr_Update, DE349641, 00974907,00973448)