If a DXF file is imported to use as a sketch.. the obsolete lines can only be deleted by if the current zoom is close enough for Fusion to identify the lines.
If there are small lines away from each other, or several small lines that need to be deleted one can not select them all at the same time and hit delete or right click delete (sometimes more effective).
You would need to zoom in to each individual line to delete.
Clean up a sketch imported from DXF is time consuming at this time.
Thanks
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