FileFormatError when loading PET CT

I would like to load PET CT images into Slicer 3.13, DICOM import works, but clicking the axial 512x512 PET image series results in:

Could not read scalar volume using GDCM approach. Error is: FileFormatError
Loading with imageIOName: DCMTK
Could not read scalar volume using DCMTK approach. Error is: FileFormatError
Could not load: 552: TK axial as a Scalar Volume

The PETDICOMExtension is installed. Any ideas?

Thank you.

There is a b/w 128x128 PET image series with modality “PT” that can be loaded, but the colored PET-CT images with modality “OT” can not.

“OT” modality means other, it is an unidentified blob of data. It can be safely ignored.

That makes sense, and I am now able to display the “TK AC” b/w series and the “TK 3D” color series.