Teamcenter OOTB configuration does not have any dataset type named "Step".
Teamcenter Admin may need to use BMIDE to manually create the custom dataset types.
Solution1. In BMIDE create a custom STEP Dataset for e.g. "PL4_STEPDataset".
2. Save and Deploy
3. Update the TC Preference TC_NX_DataExchange_Dataset_Preferences with the custom STEP Data set
Ex:
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STEP:EXPORT:EXT=stp:TYPE=PL4_STEPDats:REL=IMAN_manifestation:REF_TYPE=PL4_STEPDatset STEP:EXPORT:EXT=step:TYPE=PL4_STEPDats:REL=IMAN_manifestation:REF_TYPE=PL4_STEPDatset STEP:EXPORT:EXT=stpz:TYPE=PL4_STEPDats:REL=IMAN_manifestation:REF_TYPE=PL4_STEPDatset STEP:IMPORT:EXT=stp:TYPE=PL4_STEPDats:REL=IMAN_manifestation:REF_TYPE=PL4_STEPDatset STEP:IMPORT:EXT=step:TYPE=PL4_STEPDats:REL=IMAN_manifestation:REF_TYPE=PL4_STEPDatset STEP:IMPORT:EXT=stpz:TYPE=PL4_STEPDats:REL=IMAN_manifestation:REF_TYPE=PL4_STEPDatset
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Save it.
4. Restart all the TC services
5. Launch TC and NX
File -> Export -> STEP
Now the Dataset Type is selected as PL4_STEPDataset.