Error 27 indicates a communication issue with the controller. This issue can be fixed with a quick reset of your bike.

To reset your bike, look under the bike's top tube at the area beneath the Matrix Display. You'll see the plastic speaker grill, with a small circular hole at the end nearer the handlebars. Insert a small tool (like a pen or paperclip) into this hole and push until you hear a clicking sound. Remove the tool – the bike has now been reset and should function as normal.

If the reset did not solve the issue, please contact customer support.