ncelab and ncvlog version error conflict

I am trying to follow a tutorial on how to use NClaunch interface to compile and elaborate verilog files.  There seems to be a version conflict when I get to the elaborate step. Here is the error I get:

ncvlog_cg: *F,NBADVR: The version of the Calling tool "TOOL: ncelab(64) 10.20-s076" does not match the version of the Called tool "TOOL: ncvlog_cg(64) 08.20-s015".

When I type in ncvlog and ncelab from the terminal, the versions appear to be same 64 bit ones, 08.20-s015.

Is there any way I can change the version ncelab called by nclaunch. 

Also when I try to use ncelab on my stimulus file from the command line, I get the following error:

Unable to find a unit named 'stimulus.v' in the libraries.

I am beginner to using ncverilog and nclaunch so any help would be appreciated. 

Thanks