Email merge error - 3048

Some of my clients got the error and adding Trusted Locations for their FE & BE solved the problem of both the 3048 error and the .laccdb lock file not getting deleted. I didn't get the 3048 error until last night.
My installed version is:
Version 2201 (Build 14827.20198 Click-to-Run); 32-bit version of MS Office Professional Plus 2016

So looks like they fixed some and broke others.

For anyone interested, here's a quick way to see if you have the bug:

1. Create a new accdb
2. Create a table (Dual for me) with 1 Autonumber field.
3. Add one record
4. Insert a new module
5. Copy and paste the following code that creates a short recursive routine:


Option Compare Database
Option Explicit

Public Sub BugTest(Optional DbCount As Long = 1)
On Error GoTo errHandler
Dim rs As DAO.Recordset

Set rs = CurrentDb.OpenRecordset("Select * from Dual", dbOpenDynaset)
Debug.Print "Open Db count: " & DbCount
If DbCount < 1000 Then BugTest DbCount + 1

ExitSub:
If Not rs Is Nothing Then rs.Close
Set rs = Nothing
Exit Sub
errHandler:
Debug.Print Err.Number, Err.Description
Stop
Resume
GoTo ExitSub
End Sub

6. run BugTest procedure.

For me, the routine stops with the 3048 -Cannot open any more databases. after opening 252 (errors opening the 253rd recordset)