DFU Update fails to Connect on iOS error 94

RE: DFU Update fails to Connect on iOS error 94

Hung Bui — Thu, 04 Dec 2025 13:36:40 GMT

Hi Johnny,
Please create a new ticket and add your log and description of the issue. This is an old ticket.

RE: DFU Update fails to Connect on iOS error 94

Johnny_8 — Thu, 04 Dec 2025 13:22:12 GMT

Are there any news about this? We also have this error 94 problem, in our case even rebooting the phone does not solve the problem. The error is generated after entering in the "Enabling DFU mode" phase. We are using iOS NordicDFU library (4.16.0).

RE: DFU Update fails to Connect on iOS error 94

Hung Bui — Thu, 13 Jul 2023 09:25:11 GMT

Thanks Ryan for the info. I will get our app developer to take a look. They are on vacation now and will be back in about 3 weeks.

RE: DFU Update fails to Connect on iOS error 94

RyanTemp — Thu, 13 Jul 2023 08:16:52 GMT

Hi Hung
94 was from nordic_dfu 6.0.1 Flutter library
I could managed the update using nRF connect as soon as it attempt to connect.

    await NordicDfu().startDfu(deviceId, zipFile.path,
        onProgressChanged: _onDfuProgressChanges,
        onDfuCompleted: _onDfuCompleted,
        onError: _onDfuError);

RE: DFU Update fails to Connect on iOS error 94

Hung Bui — Wed, 12 Jul 2023 15:16:19 GMT

Hi Ryan,
Error 94 was printed on your app ? And if you use our nRF Connect to do DFU it worked ?
I'm not so sure what error 94 is in this case. Could you check in your app what is the error code come from, either from the phone side or from the DFU target ?

RE: DFU Update fails to Connect on iOS error 94

RyanTemp — Wed, 12 Jul 2023 05:08:58 GMT

We managed to resolve this by rebooting the iPhone, perhaps turning on and off the Bluetooth may have worked also.

I would still like a response on how to decipher error code and how frequently we can expect to see this error.