Unable to debug "There was a problem with the requested skill's response" - alexa

Question

Background: I am working through a flashcard Skill that enables Alexa to ask basic questions about a programming language. The user can choose between Ruby, Python or JS.
The progression goes:
LaunchRequest welcomes the user, then asks for their language preference
User responds, causing SetLanguageIntent to trigger
A question is then asked of the user
However, I am unable to get past the SetLanguageIntent without encountering "There was a problem with the requested skill's response".
Here is the dialogue:
As one can see from the response, SetLanguageIntent is activated properly with the slot ruby also matching correctly.
"request": {
"type": "IntentRequest",
"requestId": "amzn1.echo-api.request.743f750e-96d9-4ef9-aeba-e0aec2e45afb",
"timestamp": "2018-09-12T13:35:25Z",
"locale": "en-US",
"intent": {
"name": "SetMyLanguageIntent",
"confirmationStatus": "NONE",
"slots": {
"language": {
"name": "language",
"value": "ruby",
"resolutions": {
"resolutionsPerAuthority": [
{
"authority": "amzn1.er-authority.echo-sdk.amzn1.ask.skill.ee34487d-d343-4deb-ab6c-193777c92aa8.languages",
"status": {
"code": "ER_SUCCESS_MATCH"
},
"values": [
{
"value": {
"name": "ruby",
"id": "58e53d1324eef6265fdb97b08ed9aadf"
}
}
]
}
]
},
"confirmationStatus": "NONE"
}
}
}
However, at this point the error message "There was a problem with the requested skill's response" always appears. There are no errors reported on CloudWatch Logs.
For reference, here is the SetLanguageIntent code. As noted in the comment, the test "Okay" should at least have been said. However, it does not get executed.
'SetMyLanguageIntent': function() {
this.response.speak('Okay'); //this should at least have been said
this.attributes.flashcards.currentLanguage = this.event.request.intent.slots.languages.value;
var currentLanguage = this.attributes.flashcards.currentLanguage
this.response
.speak('Okay, I will ask you some questions about ' +
currentLanguage + '. Here is your first question. ' +
AskQuestion(this.attributes))
.listen(AskQuestion(this.attributes));
this.emit(':responseReady');
},
Any help is much appreciated!
Edit: updated with slot names

Answer 1

I see a problem with your code. This is why you're probably having an issue. You are trying to access an undefined property this.event.request.intent.slots.languages.value. The mistake is word languages. It should be language.
So the way to acces a slot value should be:
this.event.request.intent.slots.language.value

Answer 2

I fixed the same problem for myself by simply adding a cardRenderer() to my response. Like this:
this.response.speak("my text").cardRenderer("ttitle","some content","image");
In the test simulator's device log, I noticed the card renderer show up, saying the skill responded with a failure. So I took a shot and it worked. Hopefully this fixes it for you too!