This is a 2011/2012 issue-and not a big one.   I know that a variable called thickenss is automatically generated by thin features and the sheetmetal base feature and going back to 2009-I guess-if I established a global variable while creating my layout sketch for thickness, then thin-features and sheet metal would go ahead and use it.

Now I get an 'equation is invalid' notification.  It's nota  big deal.  I create a varaible called thk and link thickness back to it when it finally shows up.

Anyway, I was just curious whether anyone saw this, had insights on working around it and it anyone knew the reason for the change.

Thanks

John Burrill