This is a custom MPxFileTranslator that can be loaded as plug-in into Maya. With this loaded as plug-in you can reference any `.txt` file on disk. To make this work save a `.ma` scene next to the text file with the same name and reference the txt file. What should happen is that the `.ma` should be loaded three times within a single reference no…

mpxfiletranslator_crash_example.py

"""This is a custom MPxFileTranslator that can be loaded as plug-in into Maya. 

With this loaded as plug-in you can reference any `.txt` file on disk. 
To make this work save a `.ma` scene next to the text file with the same name 
and reference the txt file. What should happen is that the `.ma` should be 
loaded three times within a single reference node in Maya. 

Note: it crashes in Maya 2018 when saving the scene and then reopening the scene.

"""

import maya.OpenMayaMPx as omMPx
import maya.cmds as cmds
import os
import logging


log = logging.getLogger("CustomTranslator")



class CustomTranslator(omMPx.MPxFileTranslator):
    """Custom MPxFileTranslator
    
    Reference a .txt file that is next to a .ma file.
    
    Then this should reference the .ma file three times
    as if it's the .txt file.
    
    """

    typeName = "custom"
    extension = "txt"

    def __init__(self):
        omMPx.MPxFileTranslator.__init__(self)

    def haveReadMethod(self):
        return True

    def haveNamespaceSupport(self):
        return True

    def defaultExtension(self):
        return self.extension

    def filter(self):
        return "*.{0}".format(self.extension)

    @classmethod
    def creator(cls):
        return omMPx.asMPxPtr(cls())

    def identifyFile(self, fileObject, buffer, bufferLen):

        # Ensure filename ends with extension
        fname = fileObject.resolvedName()
        ext = ".{0}".format(self.extension)
        if fname.endswith(ext):
            return self.kIsMyFileType

        log.info("Not my file type")
        return self.kNotMyFileType

    def reader(self, fileObject, optionString, accessMode):

        fullPath = fileObject.resolvedFullName()
        ma_path = fullPath[:-(len(self.extension) + 1)] + ".ma"
        
        # Reference the other file 3 times (for testing)
        cmds.file(ma_path, i=True, namespace="a", returnNewNodes=True)
        cmds.file(ma_path, i=True, namespace="b", returnNewNodes=True)
        cmds.file(ma_path, i=True, namespace="c", returnNewNodes=True)

        return True


def initializePlugin(obj):
    plugin = omMPx.MFnPlugin(obj, "Roy Nieterau", "0.1")

    # Register
    try:
        plugin.registerFileTranslator(
            JSONTranslator.typeName,
            None,
            JSONTranslator.creator,
            None,
            None,
            True
        )
    except RuntimeError, e:
        mc.warning("Can't register plug-in node "
                   "{0}: {1}".format(JSONTranslator.typeName, e))


def uninitializePlugin(obj):
    plugin = omMPx.MFnPlugin(obj)

    # Deregister
    try:
        plugin.deregisterFileTranslator(
            JSONTranslator.typeName
        )
    except RuntimeError, e:
        cmds.warning("Can't deregister plug-in node "
                   "{0}: {1}".format(JSONTranslator.typeName, e))

I stumbled across this while researching MPxFileTranslators and was wondering if you ever filed this as a bug with Autodesk? Did you find any viable workarounds? Did this work in previous versions of Maya?

I'd really love to use File Translators with our referencing pipeline, but this crash makes that difficult. Cheers!