It is no longer possible to log in to the same Survey Anyplace account from multiple devices simultaneously if you're on the free, essential or professional plans. Similarly, simultaneous logins are no longer allowed across different browsers. Having more than one person logged into the account has created issues in the past of losing work that has been done on the survey.
When a second person tries to log in to the account, they will see this warning message. The second person can choose to continue which will make all other open logins on the same account inactive, or to cancel the login and they will return to the login page.
If you want to have the capability for more than one team member to work on the account, sign up for the enterprise plan. This plan has a great team management feature which allows you to create accounts for all of your teammates. Contact us for more information on enterprise plans and pricing.