This has been happening increasingly, when I have a sheets.add or sheets.delete in excel VBA. After searching and searching I finally found the official Microsoft support pa
Check if Microsoft Visual Basic for Applications Extensibility is being referenced in the project.
You can check that in the Tools/References Menu on the Visual Basic window of the project.
Referencing Visual Basic for Applications Extensibility prevents the program having its execution suspended:
Excel helps says specifically:
A change was made programmatically to the project using the extensibility (add-in) object model. This prevents the program from having execution suspended. You can continue running, or end execution, but can't suspend execution.
You are unable to step through code when making changes to the project (dynamically eg using InsertLine etc). the code can be run but not stepped through.