Example C:\Users\user\AppData\Local\slicer.org\Slicer 5.4.0\lib\Python\Lib\site-packages\pydicom\valuerep.py:443: UserWarning: Invalid value for VR UI: 'X.XXX.XXXXXXX.XXXXXX.088888.XXXXXX.XXXXXX.XXXXXX'. Please see <https://dicom.nema.org/medical/dicom/current/output/html/part05.html#table_6.2-1> for allowed values for each VR. The error occurred due to 088888 . The number for the UID cannot start with 0. It's not a fatal error, it's just a warning. Below are the note on UID Encoding Rules . Registration authorities may distribute components with non-significant leading zeroes. The leading zeroes should be ignored when being encoded (i.e.,"00029" would be encoded "29"). To suppress specific warning messages in Python, you can use the warnings module. import warnings # Ignore specific warnings warnings.filterwarnings("ignore", message="Invalid value for VR UI:*") Reference - https://dicom.nema.org/medical...