How can I assign multiple contacts to a task in 6.7.5?

Basically you need to create 2 M:M Relationships, one between Tasks and Contacts and another one between Tasks and Leads.

By creating those relationships you will be able to assign Contacts and Leads to an existing Task through theirs respective subpanels.

Regards

Basically you need to create 2 M:M Relationships, one between Tasks and Contacts and another one between Tasks and Leads.

By creating those relationships you will be able to assign Contacts and Leads to an existing Task through theirs respective subpanels.

Regards