This error is caused by Login IP ranges being set in Luminate CRM, and Luminate Online trying to connect using one that is not whitelisted.  To correct this issue:
  1. Login to Salesforce
  2. Setup > Manage Users > Profiles
  3. Click on Luminate CRM API User
  4. Select the Luminate Online API Ranges
  5. Select New and add the IP address that is showing from the most recently login failures.  
  6. Click the checkbox to acknowledge your IP address is not included in the range.
  7. Save the changes.
The Luminate IP ranges post 5/1/18 are listed below:
 
STARTEND
74.123.152.074.123.152.255
74.123.153.074.123.153.255
74.123.154.074.123.154.255
74.123.155.074.123.155.255
If you need to find the most recent login IP's to add to the whitelist:
  1. Login to Salesforce
  2. Setup > Manage Users > Users
  3. Click on the Integration User
  4. View the login history and take note of the source IP.
Note: If you do not want to restrict what IP addresses can be used by the Integration User then you can delete the current IP's set and this would allow the user to be able to login in from any location instead of being restricted by the Login IP ranges.