DS-7616NXI-K2 can't access ISAPI URL - Invalid Operation - firmware V4.82.000

[jefft4]

I have a DS-7616NXI-K2 / 16P, running the latest firmware V4.82.000 build 240224.

The integration connects fine, but doesn't receive events from the NVR. The HA log shows a HTTP 403 response to ISAPI requests:
`Logger: custom_components.hikvision_next.isapi
Source: custom_components/hikvision_next/isapi.py:804
integration: Hikvision NVR / IP Camera (documentation, issues)
First occurred: 09:30:54 (532 occurrences)
Last logged: 18:28:41

Unexpected exception | Cannot fetch state for io | Client error '403 Forbidden' for url 'http://192.168.9.222/ISAPI/System/IO/inputs/901'`
... and 500+ similar errors.

If I try to hit that ISAPI URL from my browser, I get this:
<ResponseStatus xmlns="http://www.hikvision.com/ver20/XMLSchema" version="1.0"> <requestURL>/ISAPI/System/IO/inputs/901</requestURL> <statusCode>4</statusCode> <statusString>Invalid Operation</statusString> <subStatusCode>invalidOperation</subStatusCode> </ResponseStatus>
The user is admin on the NVR and a number of cameras have 'Notify surveillance centre' set.
HTTP, HTTPS, RTSP, Websocket, IoT Monitoring and ONVIF are all enabled.

There is no option in the NVR UI to enable ISAPI as described in the integration's instructions - I have options of HikConnect, ISUP and OTAP services under 'Platform Access' and ONVIF under 'Integration Protocol'.

Has something changed in the newer firmware? I can't see how to enable ISAPI and these responses suggest that it may not be enabled by default, or the query schema has changed.

[maciej-or]

Most likely sth has changed in the latest firmware if it worked before. I will try to skip this error in the next release.

[jefft4]

Just to ensure we're clear - the ISAPI connection is not working. The error isn't one we can simply ignore, I think it's showing that, as you say, the latest firmware has changed -, and the integration needs to follow.

[maciej-or]

Please check in your web browser a basic request: http://192.168.9.222/ISAPI/System/status
Login form should appear and then you should get DeviceStatus XML.
My NVR stopped receiving fw updates last year so I'm still on V4.62.210. I believe ISAPI switch must be somewhere, you could check firmware change log as well. It should be mentioned.

[jefft4]

That basic query returns a response. I'll find the release notes at the weekend and see if they say what changed since your version. Happy to test things if you can make the changes once we find the right endpoint.

[maciej-or]

So ISAPI works. Maybe they only disabled specific endpoints.