MXF (proxies) files for Premiere

Does anyone in this communtiy know how to convert/import MXF files to proxies for Premiere 14.0.4?

I believe I have exhausted my efforts and my knowledge base.

Is this inherent in Media Encoder?

Am I not selecting the correct encode/ingest formats?

My iMac is fine, that's not the issue (4 GHz Quad-Core Intel Core i7, 

32 GB 1867 MHz DDR3, AMD Radeon R9 M395X 4 GB)

Yes, I am willing to admit this is operator error.  13% of my files would not convert (all MXF), but does Media Encoder 14.0.4 have settings for this request?  I tried a third party conversion (MXF to QuickTime via MXF video converter) but the quality was too diminished.

Thank you in adavance