Hi,
Thank you for contacting us and I'd be happy to assist.
It is strange that you're still seeing the warning about Toolset connection, even when the Toolset plugins have been removed for quite some time.
Can you please confirm that no Toolset plugin is active at the moment? If yes, you can install a plugin like "Transients Manager" and see if any expired/cached transients are still added?
Toolset plugins don't automatically remove their data upon deactivation or deletion. If you want to completely remove all Toolset data from the database, it would be best to re-activate all the Toolset plugins that you previously had and then remove the components, manually. Once, removed, you can deactivate and delete the Toolset plugins again.
Toolset Types:
1. You can delete all Custom Fields in Toolset > Custom Fields > Custom Fields Control. This will also delete their database entries.
2. You can delete the unwanted posts from custom post types like you delete native posts or pages. One by one or checking many and pressing "delete" in the bulk actions. Then, later also delete the actual post type, to erase all traces.
3. The same can be repeated from custom taxonomies.
Toolset Views, Blocks, Layouts:
You can delete views, layouts, content Templates in their respective admin screens.
Toolset Forms:
Forms can be deleted the same way as well, from their own management screen, in the Toolset menu.
Toolset Access:
Access rules can be deleted and reset in Toolset > Settings > Access
Database tables:
Toolset adds some custom tables in the database starting with the prefix "_toolset_" and you can delete them after Toolset plugins have been removed.
I hope this helps and please let me know if you need any further assistance around this.
regards,
Waqar