I'm getting an error after logging into umbraco on one of our live sites. It was running fine prior to today. It seems to be occurring due to the post login update check (/umbraco/backoffice/UmbracoApi/UpdateCheck/GetCheck). When I run locally I can see this is causing a 500 error as below. Any ideas?

System.Web.Services.Protocols.SoapException: Server was unable to process request. ---> System.Data.SqlClient.SqlException: Connection Timeout Expired. The timeout period elapsed during the post-login phase. The connection could have timed out while waiting for server to complete the login process and respond; Or it could have timed out while attempting to create multiple active connections. The duration spent while attempting to connect to this server was - [Pre-Login] initialization=209; handshake=12065; [Login] initialization=0; authentication=0; [Post-Login] complete=2035; ---> System.ComponentModel.Win32Exception: The wait operation timed out --- End of inner exception stack trace --- at System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, UInt32 waitForMultipleObjectsTimeout, Boolean allowCreate, Boolean onlyOneCheckConnection, DbConnectionOptions userOptions, DbConnectionInternal& connection) at System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, TaskCompletionSource1 retry, DbConnectionOptions userOptions, DbConnectionInternal& connection) at System.Data.ProviderBase.DbConnectionFactory.TryGetConnection(DbConnection owningConnection, TaskCompletionSource1 retry, DbConnectionOptions userOptions, DbConnectionInternal oldConnection, DbConnectionInternal& connection) at System.Data.ProviderBase.DbConnectionInternal.TryOpenConnectionInternal(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource1 retry, DbConnectionOptions userOptions) at System.Data.SqlClient.SqlConnection.TryOpenInner(TaskCompletionSource1 retry) at System.Data.SqlClient.SqlConnection.TryOpen(TaskCompletionSource`1 retry) at System.Data.SqlClient.SqlConnection.Open() at umbracoUpgradeChecker.BusinessLogic.Logger.Log(String server, Int32 major, Int32 minor, Int32 patch, String comment) in D:\Dev\UpgradeChecker\umbracoUpgradeChecker\BusinessLogic\Logger.cs:line 29 at umbracoUpgradeChecker.CheckForUpgrade.CheckUpgrade(Int32 versionMajor, Int32 versionMinor, Int32 versionPatch, String versionComment) in D:\Dev\UpgradeChecker\umbracoUpgradeChecker\CheckForUpgrade.asmx.cs:line 52 --- End of inner exception stack trace ---