Elsa 3 error executing csharp expression - The memory block 'Elsa.Expressions.Models.MemoryBlockReference' does not exist

## Description
Getting error - 'The memory block 'Elsa.Expressions.Models.MemoryBlockReference' does not exist' when a accessing workflow input inside "Elsa.FlowDecision" using csharp expression **"Input.Get(\"IsError\")"**

## Steps to Reproduce

1. Workflow uses custom activities and FlowDecision. Workflow expects input of type boolean
2. The flow is designed using designer and WorkFlow JSON is exported and run from .Net 8 application using code below


Attached is the workflow json generated

[elsa3.json](https://github.com/elsa-workflows/elsa-core/files/15082909/elsa3.json)

Please advise.