We have observed that mostly when user's profile do not have access to Mobile, Name, SMS Opt Out field of Lead or Contact object, this error occurs. 

User need to have access to fields which he is using while sending out message (e.g. mobile number field, Name field and merge fields which you are using in SMS Template). Can you please provide access to these fields to that user's profile and try again?

Also you need to have access to objects which belongs to SMS Magic Interact. You can refer below link for more detail on permissions required to profile to be able to use SMS Magic to send out messages-:


You need to give FLS (Field Level Security) access to below custom objects and the respective fields from profile page itself:
  1. SMS History,
  2. SMS Sender Id
  3. SenderId Profile Map
  4. SMS Templates
  5. SMS Template Type
  6. Incoming SMS
  7. Action On Incoming SMS
  8. Incoming Lookup
  9. Incoming Alert Configuration
  10. Opt-out Setting

To do the same:

  • Go to profile UI to which you want to give access to SMS Magic—In the Field-Level Security section, click View next to the object you want to modify, and then click Edit.

  1. Specify the field's access level.
  2. Click Save.
Once you give required access to user profile, it should resolved notified problem for that user. 
Note -: From SMS Magic Interact version 1.46 onward, also make sure that all the Campaign Member fields are at least read only to that user who is trying to send SMS from Campaign.