1.2 KiB
NullReferenceException while setting SqlConnection.ConnectionString to an empty string or null.
Symptoms
When an application tries to set the ConnectionString property of the SqlConnection object to an empty string or null value, a NullReferenceException is thrown. This exception occurs when .NET Framework 4.7.2 is installed on the OS hosting the application.
Cause
.NET Framework 4.7.2 includes a change that increases the default connection retry count for connections to Azure SQL Database to two.
This change sets the internal value of the retry count without validating if the ConnectionString is a non-null or non-empty value,
which results in the NullReferenceException.
Impact
The impact is limited to applications using the SqlConnection.ConnectionString API to set an empty connection string, which now throws an exception.
Workarounds
No known workarounds with .NET Framework 4.7.2.
Resolution
This issue has been fixed in the latest update to .NET Framework 4.7.2 for all platforms except Windows 10 April 2018 Update.
For Windows 10 April 2018 Update, the fix will be available in the upcoming Cumulative Update.