Can't assign new material.

[Anonymous]

//Error: file C:/Program Files/Autodesk/Maya2016.5/scripts/others/renderCreateBarUI.mel line 618: Object'' not found.

[mspeer · Accepted solution]

Try a reset of your preferences.
Rename the folder prefs in folder 2017 (or 2016.5) to something like prefs_backup, or to reset everything, the folder 2017 (or 2016.5) to 2017_backup. Maya creates new folders. Detailed at:
https://knowledge.autodesk.com/support/maya/troubleshooting/caas/sfdcarticles/sfdcarticles/Reset-May...

[Anonymous]

Thank you, solved.