Sharing a sheet - viewer is prompted for a login

Betsy Green
Betsy Green ✭✭✭
edited 12/09/19 in Smartsheet Basics

I am trying to share a sheet with a colleague. I set him as a Viewer and sent him the link. He is being prompted to log in. This person does not have a Smartsheet license and just needs view only access to the sheet. Can you please help me figure out how to fix this? I thought perhaps the problem was that the sheet was stored in a workspace, so I moved it, but that didn't help.