The only problem I'm aware of with variables with this SKILL function (which is used within the corners tool) is either if the variable truly is not a legal name (which seems unlikely, if it works in ADE normally), or if you have some customization which messes with the regular expression "magic" mode.

Can you try typing:
Code:

rexMagic() 

in the CIW - does it return nil? If so, try doing:
Code:

rexMagic(t) 

and seeing if that helps.

Essentially, if you use rexMagic(nil) it will disable the handling of certain regular expression characters as special "magic" characters, and consequently the code which checks for illegal names fails. I've seen a design kit where this happened (inadvertently).

Other than that, you might want to contact BDA's support - assuming that the problem doesn't occur with (say) spectre or spectreVerilog.

Regards,

Andrew.