Error messages

[Anton V. Belyaev]

Hello,

I use Emacs from CVS and it has a lot of errors and incompatibilities.
When some error occurs, I get just a message, for example

Invalid function: "..."

is there any way to get to debugger instead of this message, to be
able to fix the error?
I believe this is a common situation and enabling the debugger in this
case is very simple, but I didnt find a way to do it.

Thanks.