My testing indicates that it isn’t the content of the files, just what PowerDirector expects to be within the various different container wrappers. H.265 content within a MP4 container would routinely crash PowerDirector when media for use was ingested into the program. Simply migrating the content into a different container, like MKV with ffmpeg, resolved the issue without compromising the quality of the audio or video.
Ffmpeg needs to be used to perform this operation, simply changing the file extension will not resolve the issue.
Perform the following with ffmpeg:
ffmpeg -i GX0001.MP4 -c:a copy -c:v copy GX0001.MKV
The above command uses the GX0001.MP4 as the input file, copies (not transcodes) both the audio and video streams and outputs the contents into the GX0001.MKV file container. The resulting file can then be ingested into PowerDirector for editing and rendering of your final output.
Have a large directory of files that need converting? Here is a simple few lines of Borne shell that can do the heavy lifting for you:
user@bsdhost:~/Video $ for i in `ls -1 | cut -f 1 -d .` do ffmpeg -i $i.MP4 -c:a copy -c:v copy $i.MKV done ; date
For further information on the HEVC/H.265 functions in ffmpeg, refer to the H.265 wiki page.