Authentication failure in 2018 R2 SDK after 2025 R3 SDK login (same credentials)

MIP
1

Hi,

I have two integrations that use different versions of the Milestone MIP SDK:

  • One integration uses 2018 R2 SDK

  • Another integration uses 2025 R3 SDK

Both integrations connect to the same Milestone XProtect VMS using the same Windows AD credentials (Negotiate).

Initially, both SDK versions work correctly. I am able to log in successfully using both the 2018 R2 SDK and the 2025 R3 SDK on the same PC.

However, after I connect once using the 2025 R3 SDK, any subsequent login attempt using the 2018 R2 SDK on the same machine fails with an InvalidCredentialsMIPException.

The same credentials continue to work:

  • On another PC using the 2018 R2 SDK

  • On the same PC using the 2025 R3 SDK

This suggests the issue is machine-specific and occurs only after the newer SDK has been used. Suspect there may be some authentication or session state (possibly related to Windows AD/Negotiate or SDK-level caching) that is being left behind by the 2025 R3 SDK and is not compatible with the 2018 R2 SDK.

Could you please advise if there are any cleanup required when switching between SDK versions on the same system?

Thank you.

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3

In my testing I cannot log in to a newer XProtect system using a MIP SDK 2018 R2 sample. I consistently get a ServerNotFoundMIPException (NOT InvalidCredentialsMIPException).

One likely reason is that older SDKs might rely on legacy IIS SOAP/ASMX endpoints during discovery/login, and these have been deprecated for years and are being removed in newer VMS releases (i.e. ServerCommandService.asmx is now removed). Ref. release notes.

You didn’t mention the target XProtect version: Which VMS version are you connecting to?