MXF decode Error on premiere cc2017

hi,

when i import files mxf (xdcam_422_50i) into my premiere project i get an mxf decode error (and frame xy was substituted).

if i try to export the files i get an error again.

the only way to get work done is to set the sequence setting to 50p instead of 25i frames...but then at least some files are out of sync.

any ideas? thx

g

j