Converting vtk to vtu

I have all of my current files in .vtu format i cannot open it on paraview 5.8.1. Is there an easy way to convert each of these files into .vtk files?
Thank you

ParaView can read .vtu files. Normally I would suggest converting by loading the .vtu file in ParaView and writing out a .vtk file.

Are you sure there is not a problem with the format in your .vtu file?

Hey Kenneth thank you for your reply! i got it working after pasting the following into my cfg file: OUTPUT_FILES= PARAVIEW_ASCII
After i have added this and run it my .vtk file could be outputted on Paraview 5.8.1.