Which version of Retroarch are you using? I was using 1.3.2 just fine until I decided to update to 1.3.4 today. Now I am getting the same issue. Maybe the command line changed?
Great plug in Unfortunately it stopped working for me after I updated it to version 1.3.5 (I previously used 1.3.1). GameEx doesn't seem to load it although everything is set up properly. If try to change the config it boots up XPADDER as it should when I click on the XPADDER icon inside your plug in. But XPADDER doesn't start when I load a game (with any emulator).
I wasn't complaining or anything. In fact I appreciate this level of service very much I just wanted to know if this issue is being looked into because tthurman told us more or less 'I am using an older MAME version so I can't help'. No pressure, just curiosity
Thank you! Wouldn't have bumped if we got something like 'noted!' or 'looking into this' https://github.com/mamedev/mame/blob/master/src/mame/drivers/segas32.c You can see the list at the very bottom of the page. For a visual reference: http://www.system16.com/hardware.php?id=709 and http://www.system16.com/hardware.php?id=710