I created a dvds file using version 3.2.1. This creates a short DVD from an MKV created by joining 2 VOBs from a genuine longer DVD created by a Panasonic VHS to DVD recorder, then cropping this MKV using a command line and ffmpeg. So I am starting from an MKV containing genuine DVD compatible mpeg2.
The new short DVD was created using COPY for Both Audio and Video as they were from a DVD. With V3.2.1 that worked perfectly after I had chosen ff-mpeg VBR mode with 1-Pass. (Initially it created a DVD using CBR which I did not need or want.)
Now in V3.3 b4 there are two problems. First a right click on Title 1 brings up the file details (Copy etc) but clicking OK does something silly. It changes my "Play" button to have the full MKV filename instead of "Play". This is too long and fails. V3.2.1 does NOT do that. Then there must be some other change I cannot find as it will not encode a DVD but fails with a complex message about missing files! I did manage to make a DVD after first installing V3.3 b4 but probably didn't look at Title 1 Properties. That seems to be where everything goes wrong.
So, currently V3.3 b4 is unusable for me. V3.2.1 works perfectly and has been used on several projects.
I have also tried V3.3 b3. This has the same bug. It looks like something went wrong when the option to use video for a button was added. I have added my dvds file. Only other input is a background image and the MKV video file.