Once a museum guide robot is deployed in the real world, it is faced with the difficulty to deal with user utterances within a noisy environment. We present explorative analy- sis of the ways in which visitors signal trouble on a multi- modal level when they have difficulties in understanding the robot. Such moments of trouble are investigated in the con- text of robot-to-group situations. Analysis will give insights into the visitors conduct at moments of trouble in robot-to- single-user and robot-to-group interactions. In a limited data set, we found that members of a group show internal gaze coordination between each other when trouble occurs due to the robot’s inadequate behavior. Implications will be drawn for further developing the interactional capabilities of an au- tonomous robot system to be attentive and responsive to the users’ needs.