Hi, Clark
All ‘vis’ commands were renamed to ‘vray’ commands in version 3.60. I suppose you’re not writing that command yourself, but using a button command. If that is from the V-Ray toolbar, I pretty sure you’re using the wrong toolbar file. In this case just load the .rui file from the V-Ray installation folder.
If you have this error as a result of a script or macro, just change the command prefix