4K (Ultra HD, 3840 x 2160) video is now supported in the 64 bit version of DVMP Pro 7. The 64 bit version is needed because it provides the extra memory needed to decode and process such large video frames.
If you are still using a 32 bit version of Windows, this is only capable of running 32 bit software, so you can only run the 32 bit version of DVMP Pro. This means that you will probably not be able to process 4K video if you are using a 32 bit version of Windows.
4K video files created by some camera models contain video that is encoded in AVC/H.264 format, while others are in HEVC/H.265 format. If your camera model uses HEVC/H.265 encoding then you will need to install a third-party HEVC/H.265 video decoder in Tools > Options > Video Decoders > HEVC/H.265 Video Decoder. The best such video decoder is included in the popular free "LAV Filters" package. See the HEVC Video Decoder Recommendation section for more details of the LAV Filters package and where to find it.