1. Artefacts in Vegas 14 appears when GPU acceleration is turn on and turn off.
2. I have recodred video by Panasonic LX7 (1080p, 50fps).
3. 

General
ID                                       : 0 (0x0)
Complete name                            : C:\Users\Win10x64\Desktop\00034.MTS
Format                                   : BDAV
Format/Info                              : Blu-ray Video
File size                                : 6.17 MiB
Duration                                 : 1 s 899 ms
Overall bit rate mode                    : Constant
Overall bit rate                         : 27.2 Mb/s
Maximum Overall bit rate                 : 28.0 Mb/s

Video
ID                                       : 4113 (0x1011)
Menu ID                                  : 1 (0x1)
Format                                   : AVC
Format/Info                              : Advanced Video Codec
Format profile                           : High@L4.2
Format settings, CABAC                   : Yes
Format settings, ReFrames                : 2 frames
Codec ID                                 : 27
Duration                                 : 1 s 940 ms
Bit rate mode                            : Variable
Bit rate                                 : 25.9 Mb/s
Maximum bit rate                         : 26.5 Mb/s
Width                                    : 1 920 pixels
Height                                   : 1 080 pixels
Display aspect ratio                     : 16:9
Frame rate                               : 50.000 FPS
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Scan type                                : Progressive
Bits/(Pixel*Frame)                       : 0.250
Stream size                              : 6.00 MiB (97%)

Audio
ID                                       : 4352 (0x1100)
Menu ID                                  : 1 (0x1)
Format                                   : AC-3
Format/Info                              : Audio Coding 3
Mode extension                           : CM (complete main)
Format settings, Endianness              : Big
Codec ID                                 : 129
Duration                                 : 1 s 952 ms
Bit rate mode                            : Constant
Bit rate                                 : 192 kb/s
Channel(s)                               : 2 channels
Channel positions                        : Front: L R
Sampling rate                            : 48.0 kHz
Frame rate                               : 31.250 FPS (1536 spf)
Bit depth                                : 16 bits
Compression mode                         : Lossy
Stream size                              : 45.8 KiB (1%)

Text
ID                                       : 4608 (0x1200)
Menu ID                                  : 1 (0x1)
Format                                   : PGS
Codec ID                                 : 144
Duration                                 : 1 s 436 ms

4. Here are files (oryginal from camera, compressed in Vegas 13 and Vegas 14 (this files are slow down, for better artefacts look;)
https://www.dropbox.com/sh/i06d1ey8u16w10g/AAAJ9mgEXbDmsk9p9-_FUDj6a?dl=0
 

5. I dont use any effects. I have tried to reinstall Vegas 14 many times and nothing helps.

Have no artefacts (VP14)

Your original .MTS file is OK for me in VP13 and 14.

In your screen capture, the event is stretched and slightly looped. Is that intentional? Maybe you could save the project.

Looks like you are using the x264vfw codec. Why? It's generally not recommended for us in Vegas. I can't open those compressed files because I don't have that codec installed. What is your delivery destination for the files?

There is no diferences beetween stretched and real time video i Vegas 14. Artefacts allways appears in the same places.

No problem in other video editing software.

I use x264vfw becouse it gives me best video quality (in my opinion). Can you suggest better codec?

I will play this movie only on PC.

To my opinion, we would need this clip as the original file as recorded by the camara. Not encoded to any other codec.

Then we could test for you if we see that behaviour in the original file too. Or if not. That is an important point. Because if you see the artefacts with Vegas in the timeline, then it can be the Vegas decoder. Or if you see it not in the Vegas timeline, then it will be the encoder that you use.

My impression is that you see artefacts in the encoded files only. But is that true?

I would recommend to use the internal Mainconcept AVC encoder or the internal Sony AVC encoder anyway.

If you perfer to use external encoders, then I would choose another workflow (encode to intermediate codecs like Cineform, and encode that to your final file in TMPGenc). TMPGenc has a very good quality, but is not free of charge.

I see artefacts in Vegas Pro 14 timeline, an after render (i tried 3 diferent codecs in Vegas 14) i see them in the rendered file while playing.

So it has to be problem with Vegas 14 decoder. Whole project made in Vegas 14 has this artefacts in timeline, and in rendered file (codec i render is no problem).

Oryginal file from my camera is here:

www.dropbox.com%252Fsh%252Fi06d1ey8u16w10g%252FAAAJ9mgEXbDmsk9p9-_FUDj6a%253Fdl%253D0

File edited and compressed in Vegas 13, or Magix Video Pro looks great!

Hmm, I have imported the original file in Vegas Pro 14 (I cannot open the other two files).

I see no artefacts at all.

Can it be that you have installed codec packages? Codec packages can make problems!

I use x264vfw becouse it gives me best video quality (in my opinion). Can you suggest better codec?

I will play this movie only on PC.

Actually if you can get it to work in Vegas and in your own PC player, and you want to render totally within Vegas, then x264vfw may be a good choice. Others would be either Sony AVC or MainConcept AVC, or render externally with a more up-to-date x264 codec to an MP4 container. You could use Vegas2Handbrake for that.

I don't know why you are seeing artefacts in the footage on the timeline. It's unusual and we've covered the usual causes. I suggest you submit a support request at http://support.magix.com/vegas , including as much detailed information about the problem as you can.

I have tested Vegas 14 and clips from my camera on another computer. Fresh windows 10 instalation, newest Vegas 14. There are the same artefacts as on my computer in Vegas 14.

Wolfgang S. - In other software for video editing there is no problem with artefacts.

Wolfgang S. - In other software for video editing there is no problem with artefacts.

I believe that you see the artefacts. But I have tested it here for you on one of my machines, and I have not seen the blocking that you have described in your first posting. And I do not have the artefacts here on my system.

If I find the time I will test it on a second system for you too, but that will take me some hours.

Maybe it is the best idea to contact the support as suggested by Nick.

I have wrote to Magix support and waiting for respond.

Here is head by head comparision of Vegas 13 and 14. (darker collors in Vegas 14 is made by filter)

And please check frame 96 of original file from camera.

No artefacts in any frame here in VP13 or VP14.189. I looked particularly closely at frame 96.

Have tried that for you on a second machine. I have not seen artefacts, neither with VP 14 build 178 nor 189. And no blocking at frame 96.

So sorry, we are not able to repro that.

Same here on several systems, again no artefacts

For those seeing the artifacting, is your full resolution rendering quality set to best in project properties?  If so, try setting it to good (the default setting). 

I have tested many settings in Vegas 14, nothing helps. Render quality settings make no change with artefacts.

I have better, smoother playback in Vegas 13, then Vegas 14.

I tried to instal Vegas in virtual machine - the same artefacts appears:/

If I set my preview to DRAFT Full, then I see the exact artifact you are talking about. It looks like your picture above. But do not see it on any other setting. Check your PROPERTIES and make sure you are on either GOOD or BEST. This overrides the setting in the preview window. (I use V12).

Interesting, after changing the setting in preferences and then changing back, that artifact shows up in everything but BEST FULL.  I am using a GPU accelerated preview and it did not reset correctly until I rebooted Vegas 12.

edited to fix error pointed out by Nick. Thanks.

The setting is in Project Properties (not preferences):

I still don't get the artefact no matter what I set for "Full-resolution rendering quality" (in Project Properties) or "Preview Quality" (at the top of the Video Preview window).

Left is Draft Full,right is Best Auto

OK, now I get it too at "Draft (Full)" preview quality, even with "Full-resolution rendering quality" (in Project Properties) set to Best.

So it would seem that the OP's render is not being done at Best or Good Resolution. Or his properties rendering is not set up correctly.

In my case there is no diferent between render settings (Draft or Best, or any diferent).