GPT-5.1 broke my custom GPT actions

GPT builders
1

Today is rolling GPT-5.1 and my custom GPT, that uses an external MCP to do some actions is refusing to do the thing. I’ve tried updating it, but even in the actions panel of the custom GPT when I click the “Test” button beside an action I get a error response. The GPT says it doesn’t have any actions set.

3 Likes
2

Update on this:
The same Custom GPT works fine from a ChatGPT Plus suscription. Using a free or ChatGPT Go suscription it doesn’t call the actions. So, its related with the new router from GPT-5.1 in the low-tier suscriptions.

2 Likes
3

Made me fumble around all morning

1 Like
4

Same issue happened to us as a free user.

@OpenAI_Support PLEASE pay attention to this :folded_hands:

5

My GPTs got the same issue, affect many users. @OpenAI_Support please take a look at this.

2 Likes
6

I have ran into this issue and have been banging my head trying to troubleshoot it.

Since 5.1 came, I can’t get my GPT to use my MCP tool - it keeps telling me there is no tool / action available to it besides search, even when it is visible in the UI. Same thing happens when using the “Test” in the Custom GPT config UI - it shows the “Call the {URL} API with the {oprationID} operation” info box, but then tells me that it can’t use a non-existant tool or call web APIs directly.

I tried re-adding the action and creating a new GPT from scratch but neither yielded different result.

I also tried public GPTs and some of them with custom actions have a similar issue - they tell me they have tools avaialbe, but when trying to call them tell me that tool is disabled / unavilable.

(I am using the Go subscription for reference, so I can’t change the model to legacy ones)

1 Like
7

Hi everyone,

this is a wide problem, custom GPTs from big companies that rely in function calls don’t work anymore with the free/Go plans :backhand_index_pointing_down::backhand_index_pointing_down::backhand_index_pointing_down:

1 Like
8

This issue seems to occur with GPT 5.1, but in GPTs for free users there is no mechanism to choose a different model, so they are forced to use 5.1.

2 Likes
9

All my custom GPTs can’t be accessed from free account, I am getting lots of user complaints.

The same issue was encountered after rollout of gpt 5 in Aug where customers actions stopped working.

@OpenAI_Support - Guys please help us fix this or advise if your policy has changed and custom GPTs with actions would not be available from free account?

10

Hi everyone, thanks for surfacing! We're taking a look now.

2 Likes