Failing to rip movie via makemkvcon but not makemkv

[Chris Jones]

I wrote some code that i've been using for a while to automatically rip a dvd/bluray to disk when one is inserted into the drive using makemkvcon.exe. Since 1.8.9 i seem to get this message a lot:

MSG:5055,0,0,"Evaluation period has expired, shareware functionality unavailable.","Evaluation period has expired, shareware functionality unavailable."
MSG:5052,516,0,"Evaluation period has expired. Please purchase an activation key if you've found this application useful. You may still use all free functionality without any restrictions.","Evaluation period has expired. Please purchase an activation key if you've found this application useful. You may still use all free functionality without any restrictions."
MSG:5010,0,0,"Failed to open disc","Failed to open disc".

I followed another post on the forum for an older version with a newer key, tried registering and i can use makemkv to manually rip the disk (IPMAN2 bluray). when i try to run it through makemkvcon though i get that error.

This is the command line i'm using to kick off the process:
C:\Program Files (x86)\MakeMKV\makemkvcon.exe --robot --messages="E:\Media\Import\Ripped\IPMAN2 (2)\Messages.txt" --progress="E:\Media\Import\Ripped\IPMAN2 (2)\Progress.txt" --minlength=900 mkv disc:0 all "E:\Media\Import\Ripped\IPMAN2 (2)"

Any ideas? is it a bug or am i doing something wrong?
I noticed there is a makemkvcon64, does it matter which you use on a 64bit system?

Thanks