SSIS Script Task cant find reference to assembly

Question

I have an SSIS package that uses a script task to populate a datatable with data from a variety of different file types including excel.

I am using NPOI to read in t

Answer 1

For custom assemblies to be referenced and executed in Script Task, you have to add them to GAC. Here is an article with workflow.
Alternative approach - provide your own AssemblyResolver in Script task code.