If you'd like to use Check-Ins without printing labels, you can do so by removing all the labels in your event.
All printing is governed by the labels you've added to an event or a location. So, if you want to make sure no labels are printed, make sure you remove all the labels from your event.
From the Labels & Locations tab of the event, start by removing the labels from the very top tier.
Select Add/Edit Labels to make changes to the labels for the event.
Select the trashcan icon to remove the label from the event then select Save.
Removing the labels from the event tier removed the labels from all the tiers except those which are added to that specific location/folder. To ensure those labels don't print, remove the labels from the remaining tiers.
If you've removed labels, but you are seeing the No Printer Connected message on an Android or iOS station, clear the default printer in the settings and re-launch the app. The error is likely appearing because the station was previously connected to a printer and lost its connection to that printer. Once the printer is cleared, the message will no longer display.