How to fix: ThisDocument.Close freezes MS Word - vba

Question

Why is following code running from MS Word (MailMerge main document) freezing the application on ThisDocument.Close False?
Do I need to close the Scripting.Dictionary in some way other than setting the object to nothing?
There is only one instance of Word active, it is visible, ThisDocument is not the active document.
I am even explicitly activating the last opened document, even if it is already active. Not sure if I even need to set the oWorkbook and oExcel to nothing.
Sub MailMergeAlternative()
Dim oExcel As Object
Dim oWorkbook As Object
Dim oFirstCell As Object
Set oExcel = CreateObject("Excel.Application")
Set oWorkbook = oExcel.workbooks.Open(SOUBOR)
Set oFirstCell = oWorkbook.sheets(SESIT).Cells(1, 1)
Dim Dict As Object
Set Dict = MakeDictionary() ' Scripting.dictionary
Dim oDoc As Object
Dim Radek As Long
Dim Radku As Long
Radku = oFirstCell.currentregion.Rows.Count
For Radek = 2 To Radku
' ... fill Dict, use MailMerge to create new document for active record ...
Set oDoc = ActiveDocument ' the new document after MailMerge
' ... insert values, save the new document, do not close it ...
Next
Closing:
oDoc.Activate ' <== set to active, not needed
Set Dict = Nothing
oWorkbook.Close
oExcel.Quit
Set oWorkbook = Nothing ' probably not needed, closed above
Set oExcel = Nothing ' probably not needed, closed above
ThisDocument.Close False ' <== Problem
End Sub
Expected:
The code runs, creates new document(s) and closes the document which is containing the macro and from where it was called. The last active document stays open (the newly created one), or if nothing was created, Word app closes.
What is happening:
The document closes, the last active document stays open. But Word freezes and the document needs to be found in Task Manager and "brought to foreground". This is not a problem when using MailMerge alone (with additional vba work) and seems to be connected to use of Excel and Scripting.Dictionary.

Answer 1

Since you don't provide a [mcve] so that we can test exactly what you're doing it's possible that the following solution won't work for your exact environment. My test was run on the code below, which essentially creates a number of new documents then closes a document. (I have no access to your Excel content or to MakeDictionary())
I created a template (dotm) and put the code in that, closed it, created a new document from the template. This document has access to the code, via its link to the template. Closing the document will also release the template (unless another document based on it is opened). But in my test the code finished without an error.
Sub TestCloseSelfDocument()
Dim docMmMainMerge As Word.Document
Set docMmMainMerge = ActiveDocument
Dim Dict As Object
Dim oDoc As Object
Dim Radek As Long
Dim Radku As Long
Radku = 5
For Radek = 2 To Radku
Documents.Add
' ... fill Dict, use MailMerge to create new document for active record ...
Set oDoc = ActiveDocument ' the new document after MailMerge
' ... insert values, save the new document, do not close it ...
Next
Closing:
Set Dict = Nothing
docMmMainMerge.Close False
End Sub