I am trying to share a feature class from gdb as web layer by using ArcGIS Pro 2.0.0 and portal for ArcGIS and I found the error (00134: Layer's data source is not supported) but when I am using .sde database the sharing process working well after I import the database to federated ArcGIS server.
Please see the screenshot below
GDB
SDE
Is it possible to share the gdb data As web layer to ArcGIS portal?
Are you using this page on Share a Web map ... ?