same error message for me too.
ArcGIS Server Manager (above) is on another machine 'gis3' than the data I'm trying to register which is on 'gis2'.
Share the folder in "GIS2" with everyone (from Windows Explorer). Define the shared path (It will start with "\\") in Publisher folder path.
I don't have admin rights to share the GIS2 folder with everyone in the company.
Only a few people can access the GIS2 drive, but I want everyone to be able to view in an online format, the GIS data (shapefiles) stored within the GIS2 drive.
Make sure the ArcGIS Server admin account has access to the folders in question.
thanks Rebecca. However, being a novice to this, I don't know how to do that.
If you are trying to register an sde database and not a local folder, make sure you are selecting "Register Database" and then import the .sde file will proper credentials.
Take a look Register your data with ArcGIS Server using ArcGIS for Desktop—Documentation | ArcGIS for Server (for 10.3/10.4) if you haven't already, and make sure you are following the correct steps.
for 10.1 ArcGIS Help 10.1 and info on registering you database in ArcGIS Help 10.1