Dear Patric
Check the job SAP_SLD_DATA_COLLECT if it already running means please remove the job and execute RZ70 if not working follow below suggestion.
Please check the SLD_NUC RFC in sm59 Type(T),please confirm your system is a non unicode system.
If RFC is not working please create Jco RFC with program id SLD_NUC in your solman and check,have you done configuration in sldapicust t-code if not please maintain the SLD Admin user name and password and click on test.
Thanks
Mahipal