I'm getting the same errors, log history window:
---
onSetCurrentLayout "Maya Classic";
file -f -new;
preferredRenderer -makeCurrent;
// untitled //
commandPort -securityWarning -name commandportDefault;
// AbcExport v1.0 using Alembic 1.5.8 (built Dec 24 2015 17:46:02)
# pymel.core : Updating pymel with pre-loaded plugins: invertShape, mayaHIK, GamePipeline, curveWarp, CloudImportExport, tiffFloatReader, MASH, poseInterpolator, bifrostvisplugin, ATFPlugin, hairPhysicalShader, ikSpringSolver, ik2Bsolver, xgenToolkit, AbcExport, retargeterNodes, gameFbxExporter, VectorRender, OpenEXRLoader, lookdevKit, Unfold3D, Type, mayaCharacterization, modelingToolkit, deformerEvaluator, renderSetup, GPUBuiltInDeformer, fbxmaya
evalDeferred "shaderBallRendererMenuUpdate";
import arnold
// Successfully imported python module 'arnold'
import mtoa
// Successfully imported python module 'mtoa'
import mtoa.cmds.registerArnoldRenderer;mtoa.cmds.registerArnoldRenderer.registerArnoldRenderer()
Maya 2017 importing module pymel 1.0.9 (/Applications/Autodesk/maya2017/Maya.app/Contents/Frameworks/Python.framework/Versions/Current/lib/python2.7/site-packages/pymel/__init__.pyc)
// Successfully registered renderer 'arnold'
// Warning: file: /Applications/Autodesk/maya2017/Maya.app/Contents/scripts/startup/autoLoadPlugin.mel line 32: Loading plug-in "mtoa" has resulted in changes to the scene that may need to be saved. //
---
The warning on Arnold happens before:
// Error: file: /Applications/Autodesk/maya2017/Maya.app/Contents/scripts/others/drInit.mel line 1960: Object '' not found. //
Doing anything within Maya constantly triggers the Error. Deleting the files in (Mac) User / Documents / maya -> projects, didn't do anything. Starting a new scene, the constant error about drInit.mel goes away, but brings up a new one:
file -f -new;
preferredRenderer -makeCurrent;
// untitled //
// Error: file: /Applications/Autodesk/maya2017/Maya.app/Contents/scripts/others/hikCharacterControlsUI.mel line 329: Object 'hikCharacterList|OptionMenu' not found. //
But, after starting a new scene, Modeling Toolkit's icon becomes active. When restarting Maya initially, it's grayed out.