VBA Solver Call -> Solver is missing or not installed properly

I have been using Excel and VBA macros/programs to run workbooks/programs for application to vehicle crash reconstruction.

I have been using (the same) Excel Solver via a VBA call for the last 16 years. In the last few weeks when I try this routine, I get an error that says “Solver is missing or not installed properly”. I have verified this error on another computer using the same software and program. I also have verified that Solver IS included in the list of installed Add-Ins on these computers and these computers have run this program recently.

Additionally, on one of the computers, I uninstalled and reinstalled the software application that includes the program that has the VBA code and this did not solve the problem.

I suspect that some update to Office is the reason that this call to Solver in the VBA code is not working. I welcome advice on steps I can take to solve this issue.

Have you checked that you have "Analysis Toolpak" installed?

Years ago I had problem installing Solver and I fond that "Analysis Toolpak" was missing as well. Strange as "Analysis Toolpak" should be installed by default when installing Excel.

Installing "Analysis Toolpak" as a standalone made it possible for me to install Solver without any problem.

Alf

Thank you for the response.

I was poking around a little more with this issue and examined the VBA code a little closer. The macro was written a decade and a half ago with the direct engagement of a Microsoft developer.

I was running into unresolvable issues calling Solver from VBA and I ended up talking to a Microsoft coder on the phone. So some of the code came directly from that person, including the following:

On Error Resume Next
Set WB = Workbooks("solver.xla")
If Err.Number <> 0 Then
Err.Clear
Workbooks.Open(AddIns("Solver Add-In").FullName).RunAutoMacros xlAutoOpen
If Err.Number <> 0 Then
MsgBox "Solver is missing or not installed properly."
Exit Sub
End If
ThisWorkbook.Activate
End If
On Error GoTo 0
Err.Clear
Set WB = Nothing

So the message box I have been seeing came from my VBA code, not the Excel system. I commented out this code and the VBA program runs again.

I don't know what changed in the Excel environment that this code snippet causes an error, but I can investigate that at my leisure now that the program runs.

Thank you.