I needed to sync two pgs subtitle form a movie that is divided in two parts (the BD of The Lord of the Rings) So each movie comes with two PGS. I actually made it and used this method.

Correct me if I'm wrong and tell me how to rid of that runtime error from the end.

1) Drop first subtitle on BDSup2Sub, select xml/png and save/export button from file

2) Do the same with the second subtitle and export in the same folder. (Add the delay if needed)

3) Open the first and second xml with a text editor (Notepad++). Copy the subtitle events from the second in the continuation of the first one.
<Event InTC="00:00:34:14" OutTC="00:00:37:14" Forced="False">

.....


<Event InTC="03:47:52:04" OutTC="03:47:54:04" Forced="False">
<Graphic Width="799" Height="73" X="562" Y="972">chi_0710_0.png</Graphic>
</Event>
</Events>
</BDN>


Then you will have to fix this line, the bolded ones (this line is on top)

<Events Type="Graphic" FirstEventInTC="00:00:34:14" LastEventOutTC="03:47:54:04" NumberofEvents="1759"/>

Just look at the first pgs and the second one and calculate the total number of the events and add the total number there. Then look at the last line from the 2nd xml and see the runtime of the last subtitle and add it as well.

Save the file and drop it on the BDSup2Sub and then export it as SUP(BD). All these files must be saved in the same folder! So on with the PNGs files

Voilą!

THE BIG PROBLEM IS WHEN I MUX IT AND THAT FREAKS ME OUT!

When it's like 30% left to mux (I used 7.4.0), I get an instant complete message, I open the movie and there is like another hour of the movie added to the normal runtime. The subtitle works flawless and perfectly synced, same with the playback of the movie so nothing wrong with this. I noticed that it's been added the whole runtime of the first subtitle. So the movie should end at 3:45:00 and it ends at 5:15:00. When it's 3:45:00 the player just skip to 5:15:00 in a second and then the movie ends.

Please help! I'm so close to succed..