...there is no guarantee that the dose delivered to the patient is the same as planned, due to the patient's anatomical change, setup uncertainty, and organ motion during treatments. ...in vivo dosimetry (IVD) has been recommended as part of routine IMRT to monitor the actual dose delivered to the patient, detect the source of errors, and assist in adaptive therapy. ...a method that can quickly detect and classify the error source is highly desirable and needed. ...it is difficult to obtain anatomical error data from actual treatment to set the "ground truth" to train and test ML/DL models. ...the proposed ML/DL models in existing studies are based entirely on simulations, which have limited applicability to the real situation. ...the error classification system based on ML/DL models can only identify those errors in relation to which they have been trained.