Try to launch MAYA with administrator rights, and check C:/solidangle/mtoadeploy/2018/plug-ins/mtoa.mll about rights too, it helps me, i recover my arnold.// Warning: file: C:/Program Files/Autodesk/Maya2018/scripts/others/supportRenderers.mel line 64: The renderer "arnold" used by this scene, is not currently available. The "mayaSoftware" renderer will be used instead. //
// Error: file: C:/Program Files/Autodesk/Maya2018/scripts/others/pluginWin.mel line 290: Unable to dynamically load : C:/solidangle/mtoadeploy/2018/plug-ins/mtoa.mll
A dynamic link library (DLL) initialization routine failed.
//
// Error: file: C:/Program Files/Autodesk/Maya2018/scripts/others/pluginWin.mel line 290: A dynamic link library (DLL) initialization routine failed.
(mtoa) //