Legacy AprilTag OpModes must be updated to check whether the returned AprilTag is a cluster or singleton, and cast the returned detection into the correct type to access its elements. See below:

Old method for AprilTag processing

 for (AprilTagDetection detection : currentDetections) {
   // Do single Tag processing here  
 }

New method for AprilTag Singleton/Cluster processing

 for (AprilTagDetection detection : currentDetections) {
   if (detection instanceof AprilTagSingleDetection) {
     AprilTagSingleDetection singleDet = (AprilTagSingleDetection) detection;
     // Do single Tag processing here  
   } else {
     AprilTagClusterDetection clusterDet = (AprilTagClusterDetection) detection;
     // Do cluster Tag processing here  
   }
 }

For more information about how to update your OpModes to fix the breaking change see: https://ftc-docs.firstinspires.org/apriltag-clusters

About AprilTag clusters:

• Clusters are co-planar groups of two or more AprilTags wherein the position of each member tag is defined relative to a common origin
• This origin may be placed outside the bounds of the tags themselves to provide a more suitable "aiming" target
• Clusters are resilient to partial occlusion. Full 6DOF pose can be estimated from a cluster even if only a single member tag is visible. Of course, the more tags that are visible, the better and more stable the pose estimate will be
• All AprilTag samples have been updated to differentiate between standalone tags and clusters