Decompiling token error

I have problem with decompiling a token. The token is created correctly, but when I try to decompile it, the programm crashes with the error:
TypeError: jwtString.split is not a function
at Object.module.exports [as verify] (/app/node_modules/jsonwebtoken/verify.js:41:25
Seems the fault is not in my code. Am I right?

It looks like the variable jwtString is expected to be a String, but it isn’t. The error is happening in jsonwebtoken code, but it may be caused by the way you’re calling the library. Take a look at the rest of the stack trace in that error message, and find the first line that is referring to your own code. You’re probably calling library code at that point. Try logging what you’re passing to the call, and see if something looks wrong.

Thank you very much, it solved the problem.