I just wrote replies to each of your deleted posts Ted, but saw Tsuka has deleted them whilst replying which was probably for the best - thanks
@TsukaYuriko.
So back to the extension - which whether you believe me or not works fine as I have already explained and whatever the problem may be is on your end.
1) How are you importing the extension into GMS2?
2) Your posted log has a OneDrive path - working from DropBox/OneDrive folders are known to cause issues with GMS2 projects so don't use them to store your projects.
As I already explained, the steps I took are as follows:
Create a new project, go to Marketplace > My Library and find Video Player Pro for GMS 2.x.
Make sure it's updated, and import it into the project.
Run the project.
That works fine, so any errors / issues you are encountering are not anything to do with the extension itself.
You can also check that the function you say is missing is in the extension by opening the extension from the Resource Tree, double clicking "video_player.dll" and looking at the list of functions the extension includes.
It looks like this for me, with the function you say is missing at the bottom:
If it isn't listed there then you are either using an older version of the extension or the error you get when importing has caused that specific function to not be imported.
edit:
I have now tested importing the extension via My Library and by downloading the .yymp file from the Marketplace website and importing that - both work fine.