Hi elcron, 

Unfortunately, we do not have any similar reported incidents, and I am unable to reproduce this error. I'm testing with MS Access 2013 (15.0.4771.1000) and Rumba 9.4.

Can you try running vse.exe in place of esp.exe in your VBA subroutine and then manually run the script from the editor? Does it work as expected?

Can you try a simple script to see it is executes OK using VSE.exe, here is what I tested with.

Sub Main
Dim MyString as String, MyMsg as String, i as Integer
MyMsg = ""
For i = 1 to 10
EMReadScreen MyString, 80, i, 1
MyMsg = MyMsg & MyString & Chr(10)
Next i
Msgbox MyMsg
End Sub

Also, have you tried an alternative method of launching the script? I often use CreateProcess for Kernel32.dll, here is some sample code.

Option Compare Database

Private Type PROCESS_INFORMATION
hProcess As Long
hThread As Long
dwProcessId As Long
dwThreadId As Long
End Type

Private Type STARTUPINFO
cb As Long
lpReserved As String
lpDesktop As String
lpTitle As String
dwX As Long
dwY As Long
dwXSize As Long
dwYSize As Long
dwXCountChars As Long
dwYCountChars As Long
dwFillAttribute As Long
dwFlags As Long
wShowWindow As Integer
cbReserved2 As Integer
lpReserved2 As Long
hStdInput As Long
hStdOutput As Long
hStdError As Long
End Type

Private Declare Function OpenProcess Lib "kernel32" (ByVal dwDesiredAccess As Long, ByVal bInheritHandle As Long, ByVal dwProcessId As Long) As Long
Private Declare Function GetExitCodeProcess Lib "kernel32" (ByVal hProcess As Long, lpExitCode As Long) As Long
Private Declare Function CreateProcess Lib "kernel32" Alias "CreateProcessA" (ByVal lpApplicationName As String, ByVal lpCommandLine As String, lpProcessAttributes As Any, lpThreadAttributes As Any, ByVal bInheritHandles As Long, ByVal dwCreationFlags As Long, lpEnvironment As Any, ByVal lpCurrentDriectory As String, lpStartupInfo As STARTUPINFO, lpProcessInformation As PROCESS_INFORMATION) As Long

Const SYNCHRONIZE = 1048576
Const NORMAL_PRIORITY_CLASS = &H20&

Dim pInfo As PROCESS_INFORMATION
Dim sInfo As STARTUPINFO

Sub RunAndReturn(RunThisOne As String)

Dim sNull As String
Dim lSuccess As Long
Dim lRetValue As Long
Dim Path As String

Path = "c:\\temp\\"
sInfo.cb = Len(sInfo)

lSuccess = CreateProcess(sNull, "C:\\Program Files (x86)\\Micro Focus\\RUMBA\\System\\ScriptEngine\\vsp.exe " Path RunThisOne, ByVal 0&, ByVal 0&, 1&, NORMAL_PRIORITY_CLASS, ByVal 0&, Path, sInfo, pInfo)

Do While lSuccess > 0
nn = GetExitCodeProcess(pInfo.hProcess, nExitCode)
If nExitCode = 0 Then lSuccess = 0
Loop
End Sub

Sub test()
Dim Path As String
Path = "c:\\temp\\"
RunAndReturn ("Msgbox10Rows.csf")
' Script = Shell("C:\\Program Files (x86)\\Micro Focus\\RUMBA\\System\\ScriptEngine\\vsp.exe" & " " & Path & "Msgbox10Rows.csf", vbNormalFocus)
End Sub

Given that you state the issue only started to occurs last week and it appears as if multiple users were affected simultaneously, something must have changed.

Can you check for any recent Windows updates?
Can you check the host screens to ensure they have not changed (it's unlikely as you say you can run the script manually)?
Have you had any patches recently applied to your Rumba install base?

If you are unable to address the issue, I would advise you to open a ticket with Micro Focus Technical Support.