[Govnah]

One of the KODI developers pointed me to the UWP FAQ and I assume this is the issue:

Python _subprocess module is not available on UWP, so an author of the add-on must work around or not use it for UWP.

The following lines:

import subprocess, shutil, time

and…

def popenWithTimeout( command, timeout ):
    log_lines = []
    try:
        p = subprocess.Popen( command, stdout=subprocess.PIPE, stderr=subprocess.PIPE )
    except OSError:
        log_lines.append( 'error finding external script, terminating' )
        return False, log_lines
    except Exception as e:
        log_lines.append( 'unknown error while attempting to run %s' % command )
        log_lines.append( e )
        return False, log_lines
    for t in xrange( timeout * 4 ):
        time.sleep( 0.25 )
        if p.poll() is not None:
            return p.communicate(), ''
    p.kill()
    log_lines.append( 'script took too long to run, terminating' )
    return False, log_lines


Thanks!