In Strategy 2019 Update 3, you may encounter the following error when editing a document in Developer. The error reads:
"Automation Error: The object invoked has disconnected from its clients."

Developer may even crash and you may see the error:
"Strategy 2019 has stopped working. Windows can check online for a solution to the problem."

This issue is related to the layout of the document. If the layout issue is on the document's landing page, that is when Developer will crash.
This issue is resolved in Strategy 2019 Update 4. Upgrade to Strategy 2019 Update 4 or later to take advantage of the fix.