I've seen this before, though not on a fresh install. Somewhere around MODX 2.3.0, the modContext object got a 'name' field. MODX isn't finding that field, hence the error. The first thing to try is this:
log out
delete all files in the core/cache directory
clear your browser cache and cookies (or use incognito or private mode)
If that doesn't fix it, take a look at the database with PhpMyAdmin. Select the MODX db and check the modx_context table to see if it has a name field. If not, try re-running setup.
If that doesn't fix it, you may have a missing or corrupted file in your MODX install. It's fairly common if you transfer the files individually with FTP.
Last resort: Create the 'name' field yourself. It's:
Type: varchar(255)
Attributes (leave blank)
Allow Null: Yes
Default: NULL
There is also an index on that field:
Keyname: name
Type: BTREE
Unigue: No
Packed: No
Column: name
Cardinality: 3
Collation: A
NULL: YES
