[Bug] SuggestedCacheExpiry can be in the past and results in System.ArgumentOutOfRangeException: The relative expiration value must be positive.

A customer reported this issue with their InMemory OBO cache.

full exception:

System.ArgumentOutOfRangeException: The relative expiration value must be positive. (Parameter 'AbsoluteExpirationRelativeToNow')
Actual value was -18869.20:47:50.7160847.

Could be that there was an old cache with an expired token, and the expiry computed by MSAL was done in an older version, the newer version of MSAL no longer computes the expiry for OBO tokens, so the cache doesn’t know how to process it. not sure, needs to be investigated. Have not been able to repro locally.

[bgavrilMS]

Hi @petrochuk - the “sequence contains no elements” is a different problem. The tracking issue for it is: https://github.com/AzureAD/microsoft-authentication-library-for-dotnet/issues/3130

I have a PR out of it and we’re going to hotfix MSAL, most likely in a day or two. I expect MSAL 4.41.1 to have the fix.

[bgavrilMS]

What’s possibly happening is that CalculateSuggestedCacheExpiry is called in the finally clause.

So if an exception occured (e.g. during serialization to Redis), we still try to compute the cache expiry, but we will have not added a tokens to the cache. We should check if we indeed added them?