Thanks j-v.

I took your advice and converted the MP4 to constant framerate before dropping onto the Vegas timeline.

Before dropping on the timeline, I reset the project properties to another random setting, cleared any previous files in the project and then dropped the new constant rate file on the timeline....Vegas asked to change the project settings to match the MP4...said yes. When rendering the file out to a MAGIX MP4 preset, the resulting MP4 had the same issue as before!! The lyrics (credit roll) and music (from MP4) continue fine, but the video goes black after 15 seconds (different each time). I'm still puzzled as to why ver14 works perfectly...and ver17 does not work!

Here's the mediainfo for the constant framerate MP4:

General
Complete name                            : R:\Business RAW\files\2020\20-04-18 Larry Bowen music video\20200418_132020-constant high bitrate.mp4
Format                                   : MPEG-4
Format profile                           : Base Media
Codec ID                                 : isom (isom/iso2/avc1/mp41)
File size                                : 81.9 MiB
Duration                                 : 4 min 34 s
Overall bit rate                         : 2 508 kb/s
Encoded date                             : UTC 2020-04-21 02:23:46
Tagged date                              : UTC 2020-04-21 02:23:46
Writing application                      : Lavf58.42.100

Video
ID                                       : 1
Format                                   : AVC
Format/Info                              : Advanced Video Codec
Format profile                           : High@L4.1
Format settings                          : CABAC / 4 Ref Frames
Format settings, CABAC                   : Yes
Format settings, RefFrames               : 4 frames
Codec ID                                 : avc1
Codec ID/Info                            : Advanced Video Coding
Duration                                 : 4 min 34 s
Bit rate                                 : 2 243 kb/s
Width                                    : 1 280 pixels
Height                                   : 720 pixels
Display aspect ratio                     : 16:9
Frame rate mode                          : Constant
Frame rate                               : 29.880 FPS
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Scan type                                : Progressive
Bits/(Pixel*Frame)                       : 0.081
Stream size                              : 73.3 MiB (89%)
Title                                    : VideoHandle
Writing library                          : x264 core 159
Encoding settings                        : cabac=1 / ref=2 / deblock=1:0:0 / analyse=0x3:0x132 / me=hex / subme=6 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=1 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-2 / threads=6 / lookahead_threads=1 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=3 / b_pyramid=2 / b_adapt=1 / b_bias=0 / direct=1 / weightb=1 / open_gop=0 / weightp=1 / keyint=300 / keyint_min=30 / scenecut=40 / intra_refresh=0 / rc_lookahead=30 / rc=crf / mbtree=1 / crf=20.0 / qcomp=0.60 / qpmin=3 / qpmax=51 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00
Language                                 : English
Encoded date                             : UTC 2020-04-21 02:23:46
Tagged date                              : UTC 2020-04-21 02:23:46
Codec configuration box                  : avcC

Audio
ID                                       : 2
Format                                   : AAC LC
Format/Info                              : Advanced Audio Codec Low Complexity
Codec ID                                 : mp4a-40-2
Duration                                 : 4 min 34 s
Bit rate mode                            : Constant
Bit rate                                 : 257 kb/s
Channel(s)                               : 2 channels
Channel layout                           : L R
Sampling rate                            : 48.0 kHz
Frame rate                               : 46.875 FPS (1024 SPF)
Compression mode                         : Lossy
Stream size                              : 8.39 MiB (10%)
Title                                    : SoundHandle
Language                                 : English
Default                                  : Yes
Alternate group                          : 1
Encoded date                             : UTC 2020-04-21 02:23:46
Tagged date                              : UTC 2020-04-21 02:23:46

Sorry, but than I have no idea what the reason can be reading your information.
Maybe we can help you if you place your veg and the used media on a cloudserve so we can download it ( or I alone , but only by P.M.) and can try to find what goes wrong.

There's 2 spots you can turn off GPU processing now, look in the file i/o tab in preferences and make sure GPU decoding is off.

Thanks j-v and frosty!

I was not aware of the 2 GPU switch ....turned off the file i/o GPU switch and all the files rendered fine!

Over the years I've encounter many strange issues that a cured by turning off the GPU's. I wish an error would actually pop up telling you there has been an error in the GPU.

Thanks again! 😀😀

If you have not tried updating to the latest studio driver from Nvidia, try that and see if you're able to turn that stuff back on, because it does make a big difference in the playback performance you get when editing.

Edit: Nevermind, I see you only have a Geforce 760, that does not support hardware decoding, which is what was causing your issue. Upgrading your GPU will give you much better performance, so keep that in mind for the future.

Before all this virus thing hit....I was planning on upgrading the computer. Now that has been moved into the future.