Installed ND 3.2R1, discovered/imported ex3400 switch with 15.1X53-D58. Schema is downloded/present.
When I try to validate / deploy even the smallest change in the imported profiles I get lots of errors "configuration attribute is not applicable to this hardware platform" and the configuration deployment in ND fails.
Sometime schema doesn't get installed properly in Space, you can verify by going to Network Application Platform > Device Management > Edit the device > CLI editor. Check the CLI editor if you can open it properly or not.
Rather than deleting the schema from system, there is an option to Override schema while installing it which we can try.