I accidentally signed everyone out of CheckPoint. Is there a way to sign them back in?

The answer is yes, although it is not as easy as it was to sign them all out.

First of all, you should focus on correcting the employees' time since their time is more critical to your payroll accuracy. Using the Classroom Folder Check in/out Tab, sign each employee back in. If the accidental checkout was performed more than 5-10 minutes ago, you will probably want to check them back in with an override time specified by selecting the OVERRIDE TIME checkbox in the center of the window. This will allow you to check the employee back in a minute after they were accidentally checked out.

This same procedure can be performed for Student as well.