Your app has been throttled by AAD due to too many requests

Hi team,

On Sharepoint online connectors we receive more and more this error : Your app has been throttled by AAD due to too many requests. To avoid this, cache your tokens see Understanding client and server throttling in MSAL.NET - Microsoft Authentication Library for .NET | Microsoft Learn.

It's true that we use our azure app to do more things each day, in more tasks. We are using server 5.7 and if you remember, our tokens do not refresh (we have an issue about it) automatically so we use the same token during 90 days.

How can this happen ?

I think we are in the case described by Microsoft because we also receive 429 errors :

  • For client_credentials grant, i.e., [AcquireTokenForClient(IEnumerable), Microsoft Entra ID will reply with 429 Too Many Requests, with a Retry-After: 60 header.

They give 3 possible explanations : token caching not setup correctly, not calling [AcquireTokenSilent] first and the third seems more related to users.

Currently we have a lot of issues about this. Can you tell us what is happening here ? I will activate the debug log as you have told us earlier.

Hi @RJO

I just want to clarify a few things. Are you still using the SharePoint with Interactive Flow along with the 'old' connector that doesn't support mutable state i.e., you haven't created a new connector? If this is the case, the propagation of the cached token may indeed be hindered.

Yes, we still have not recreated our connectors. I understand that it can also solve this issue => prioritizing this and I get back to you asap

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I think we have solved the issue. The true problem was that the certificate of our azure app had expired. In this case, some features may not work anymore. So people must be very careful when using azure apps with M365 connectors : always check the certificate of the app !

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