new comint mod in emacs for plink (putty): Symbol's function definition is void

Question

i want to use a new comint mode for plink(putty), i put the code in init.el, but if M-x run-plink, i got below error:

let*: Symbol\'s function definition is void

Answer 1

To give this question an answer, which is also meaningful for other questions marked as duplicates of this one, but actually are about other packages not being loaded, I will give a more general answer, which should be applicable to the other questions as well.

Generally an error Symbol's function definition is void often indicates, that a package was not loaded, but then someone/something tried to use it.

So the general answer, that you probably need to (require ') in your init.el, where the package name is the name of the package which provides what is currently void.