Error persists even after removing puppet class from hostgroup

Issue

Getting this error on the capsule server this activity was performed on:

# /usr/bin/puppet agent -t
Info: Using configured environment 'production'
Info: Retrieving pluginfacts
Info: Retrieving plugin
Info: Retrieving locales
Info: Loading facts
Error: Could not retrieve catalog from remote server: Error 500 on SERVER: Server Error: Evaluation Error: Error while evaluating a Resource Statement, Evaluation Error: Error while evaluating a Resource Statement, Duplicate declaration: Class[Stdlib::Stages] is already declared; cannot redeclare (file: /usr/share/puppet/modules/stdlib/manifests/init.pp, line: 18) (file: /usr/share/puppet/modules/stdlib/manifests/init.pp, line: 18, column: 3) on node capsule.example.com
Warning: Not using cache on failed catalog
Error: Could not retrieve catalog; skipping run

Tried this possible solution - however, that does not seem to fix this issue this time.