You can’t access Toolbox on Exchange after enabling EnableSerializationDataSigning

Symptoms 

After you install the January 2023 Security Update and enable the EnableSerializationDataSigning feature, you can’t access the Microsoft Exchange Toolbox. Additionally, Deserialization fails: System.Reflection.TargetInvocationException exception message is returned, and you can’t access GUI tools in the Toolbox. 

Resolution  

To fix this issue, install the following security update:

• Description of the security update for Microsoft Exchange Server 2019, 2016, and 2013: March 14, 2023 (KB5024296)