When loading UKPMS inventory following error occurs in stage 2:
Error: Occured In process_ukp_assets While Inserting TJ Assets From HHINV_LOAD_2
ORA-00001: unique constraint (HIGHWAYS.UKPMS_TJ_PK) violated
Check if any attribute of that particular asset is not missing from the "Check DCD" part of Inventory Control Data (MAI1400) form. You can compare with the attributes visible in Asset Metamodel form Attributes tab for that asset type.
If an attribute is missing please click Create Record (green cross in the main Exor toolbar) when in "Check DCD" part of the form then select the missing attribute from the list of values and save. Click "Create View" in MAI1400 form.
If no attribute is missing simply running CLEANINV script might resolve your issue.