topic Issue with Copilot Desktop Client – File Upload Error in Firewall and Security Management

Issue with Copilot Desktop Client – File Upload Error

Sergio_Tena — Fri, 28 Nov 2025 09:47:45 GMT

Good morning,

I am experiencing an issue related to the use of the Copilot desktop client. When I attempt to upload a file through the application, I receive a file upload error. After reviewing the connection logs, I see the following message:

Action Reason: "Blocking request as configured in engine settings of Application Control".
Reason: "Application Control - HTTP parsing error occurred (2)".
Precise Error: "body filter failed in request".

I have attached a screenshot of the log showing the error.

Currently, I am running Version R81.20 Take 118 with HTTPS Inspection enabled. I have not found a compatible solution in the available SKs, because the one described in sk182330:
"Uncheck the Enable HTTP Inspection on non-standard ports for Application Control and URL Filtering check box."
does not seem applicable since the error occurs on port 443.

Is there any official solution for this issue?

Thank you for your assistance.

Issue with Copilot Desktop Client – File Upload Error

Sergio_Tena — Fri, 28 Nov 2025 10:03:50 GMT

Good morning,

Action Reason: "Blocking request as configured in engine settings of Application Control".

Reason: "Application Control - HTTP parsing error occurred (2)".

Precise Error: "body filter failed in request".

I have attached a screenshot of the log showing the error.

Is there any official solution for this issue?

Re: Issue with Copilot Desktop Client – File Upload Error

_Val_ — Fri, 28 Nov 2025 11:50:16 GMT

It looks to be very similar to sk183681. Please open a TAC request for your issue

Re: Issue with Copilot Desktop Client – File Upload Error

the_rock — Sat, 29 Nov 2025 18:04:27 GMT

SK Val gave seems relevant. One thing I would try is attempt to bypass the link listed in the error and test or even better, just to confirm, disable https inspection, install policy and see if that works.

Re: Issue with Copilot Desktop Client – File Upload Error

the_rock — Sun, 30 Nov 2025 22:13:14 GMT

@Sergio_Tena

I was thinking, in case the sk Val gave does not fix your issue, you can do bypass that I mentioned in https inspection policy, just add *substrate.office* as custom app site, thats what I usually do in my lab and works 100% of the time.

Re: Issue with Copilot Desktop Client – File Upload Error

Sergio_Tena — Mon, 01 Dec 2025 08:28:16 GMT

Hello again:

Disabling HTTPS Inspection makes the issue disappear, so it seems the problem is caused by the inspection process. I have not observed any specific errors related to HTTPS Inspection, but I will investigate further or open a support case directly. Any other ideas will be wellcome...

Re: Issue with Copilot Desktop Client – File Upload Error

the_rock — Mon, 01 Dec 2025 13:55:46 GMT

Ok, so then logically, when I mentioned about bypassing step would make sense. If you can try that with blade enabled, see if it works.

Makes sense?

Re: Issue with Copilot Desktop Client – File Upload Error

Sergio_Tena — Mon, 01 Dec 2025 14:06:08 GMT

Hello again,

The blade has always been enabled; the only thing I did for testing was to exclude a user from HTTPS Inspection to verify that a user without HTTPS Inspection could successfully upload files to Copilot.

Re: Issue with Copilot Desktop Client – File Upload Error

the_rock — Mon, 01 Dec 2025 14:19:07 GMT

Right, but what I mean is if thats the case, then bypass would be good way to test it.