Customer response is not visible when clicking on the timba survey form attached against the related record.

I am using Timba Survey for years but suddenly it stops working. After clicking on Survey link from an email it is not showing survey form.

Customer response is not visible when clicking on the timba survey form attached against the related record.

I am using Timba Survey for years but suddenly it stops working. After clicking on Survey link from an email it is not showing survey form.

Hi, 

Until recently survey links sent to customers suddely reach a "not authorised" page. We have used Timba surveys   for the last 2 years and no issues and we have made no changes. 

Test survey link: https://firstbaseit.secure.force.com/timbasurveys__survey?cId=0031p000026g26x&id=a0m1p00000HFXc3AAH

I have one salesforce user that is present in two queue. one for chatting and one for taking call. I need to stop user to take chat when he is already taking call.

How can i do this in salesforce ?