Hello,
I see this with Manticore 6.2.12
WARNING: key 'workers' is deprecated in /etc/manticoresearch/manticore.conf line 12; use 'default value' instead.
But I don't see this setting in our thinking_sphinx.conf. So perhaps thinking-sphinx inserts that automatically. But it might be a problem in later Manticore versions. Maybe remove or conditionally add that?