topic Getting 400 Error while preview the lookup activity in Pipelines

Getting 400 Error while preview the lookup activity

dineshkumarravi — Wed, 11 Jun 2025 05:50:52 GMT

Hi,

I am facing an issue while previewing the lookup activity — it shows a 400 error. However, when I run the procedure alone, it works fine, and another lookup activity is also working. For reference, I have attached a screenshot below.

Re: Getting 400 Error while preview the lookup activity

josef78 — Wed, 11 Jun 2025 10:16:53 GMT

Same problem here, on Copy Activity. When I try preview on source of copy activity (Oracle DB via on-premise gw), it returns error 400 or 408. It happens in case of more complex queries.

Re: Getting 400 Error while preview the lookup activity

v-kpoloju-msft — Wed, 11 Jun 2025 11:16:42 GMT

Hi dineshkumarravi,
Thank you for reaching out to the Microsoft fabric community forum.

When we have reproduced the issue and we are getting timeout error. Could you please let us know the latest error screenshot. is it 400 error or the time out?

Thank you for using the Microsoft Community Forum.

Re: Getting 400 Error while preview the lookup activity

josef78 — Thu, 12 Jun 2025 11:47:36 GMT

In my case, there is only code 400 or 408. But it's probably related to some timeout problem, because the error occurs with more complex and longer queries.

Re: Getting 400 Error while preview the lookup activity

v-kpoloju-msft — Thu, 12 Jun 2025 04:23:30 GMT

Hi dineshkumarravi,

After thoroughly reviewing the details you provided, I reproduced the scenario again, and it worked on my end. I used it as sample data and successfully implemented it.

This might be an intermittent issue. It is currently working for us. Please let us know if you continue to experience the same problem.

If this post helps, then please give us ‘Kudos’ and consider Accept it as a solution to help the other members find it more quickly.

Thank you for using Microsoft Community Forum.

Re: Getting 400 Error while preview the lookup activity

Anushka96 — Thu, 12 Jun 2025 08:39:04 GMT

We're are facing same issue. Anyone found a solution. I think this is happening from fabric end.

Re: Getting 400 Error while preview the lookup activity

josef78 — Thu, 12 Jun 2025 18:07:35 GMT

Hi dineshkumarravi ,

the problem is still there. I think there are three different problems or changes in behavior in the last week, but one serious.
1. If in query is some small syntax error, like a semicolon at the end for Oracle DB, it returns a nonsensical 400 error.
2. If the preview contains two columns of the same name it again returns a nonsense error 400
3. If the query is a more complex query and the preview takes more than approximately 100 seconds, it returns error 408. This is different than before, either the preview takes longer than before or there is a shorter timeout. And this is a problem because it is not possible to develop a pipeline with more complex queries.

Re: Getting 400 Error while preview the lookup activity

v-kpoloju-msft — Sat, 14 Jun 2025 11:51:11 GMT

Hi dineshkumarravi,

May I ask if you have resolved this issue? If so, please mark the helpful reply and accept it as the solution. This will be helpful for other community members who have similar problems to solve it faster.

Thank you.

Re: Getting 400 Error while preview the lookup activity

Anushka96 — Mon, 16 Jun 2025 05:17:20 GMT

v-kpoloju-msft Is there any update with that?

Re: Getting 400 Error while preview the lookup activity

v-kpoloju-msft — Tue, 17 Jun 2025 11:21:16 GMT

Hi dineshkumarravi,

I wanted to check if you had the opportunity to review the information provided. Please feel free to contact us if you have any further questions. If my response has addressed your query, please accept it as a solution and give a 'Kudos' so other members can easily find it.
Thank you.

Re: Getting 400 Error while preview the lookup activity

v-kpoloju-msft — Fri, 20 Jun 2025 03:01:57 GMT

Hi dineshkumarravi,

I hope this information is helpful. Please let me know if you have any further questions or if you'd like to discuss this further. If this answers your question, please Accept it as a solution and give it a 'Kudos' so others can find it easily.
Thank you.

Re: Getting 400 Error while preview the lookup activity

Anushka96 — Fri, 20 Jun 2025 06:27:27 GMT

josef78 Any workaround for this?

Re: Getting 400 Error while preview the lookup activity

v-kpoloju-msft — Thu, 26 Jun 2025 07:29:12 GMT

Hi Anushka96, dineshkumarravi, josef78,

We are not getting any issue while trying to access warehouse. PFBS for reference. Also Parameters cannot be used as connection strings in Fabric pipelines. Please connect to the source directly rather than using parameters.

If this post helps, then please give us ‘Kudos’ and consider Accept it as a solution to help the other members find it more quickly.

Thank you for using Microsoft Community Forum.