"Compile Error in Hidden Module: SolverCode" – Solver Fails Despite Reinstall and Repair

Question

Hi all,

I’m experiencing a persistent issue when using Excel Solver that I haven’t been able to fix, despite trying multiple troubleshooting steps.

Whenever I try to launch Solver in certain workbooks, I get the following pop-up error:

Microsoft Visual Basic for Applications
Compile error in hidden module: SolverCode.
This error commonly occurs when code is incompatible with the version, platform, or architecture of this application. Click "Help" for information on how to correct this error.

Here’s what I’ve already tried:

• Uninstalled and reinstalled the Solver add-in
• Deleted .exd files
• Checked for corrupt Solver VBA components (didn’t find any)
• Repaired Office 365 through the Control Panel

What’s strange is that Solver works fine in some files, but consistently gives this error in others—even if I manually recreate the files from scratch. All files are built in Excel and don’t contain any macros I wrote myself.

I’d really appreciate any insights into what might be causing this issue or additional steps I could try.

Thanks in advance!

Answer 1

Dear ckelly78,

Thank you for reaching out to Microsoft Support Community. We are happy to assist you.

Solver is a VBA macro that may utilize ActiveX controls. If Excel is blocking either macros or ActiveX, Solver will not be able to run.

Kindly try these steps below to see if the issue is persist:

Go to Excel > File > Options > Trust Center > Trust Center Settings.

In Macro Settings, choose Enable VBA macros or Disable with notification.

In ActiveX Settings, choose Enable all controls

Re-open Excel and try to run Solver again

We hope this information is helpful to you. If you have any other concern about this or need further assistance, please don't hesitate to reach out to us so we can take a look and keep supporting you. 
Best regards,
Viego An - MSFT | Microsoft Community Support Specialist.

Answer 2

Hello ckelly78,
It has been a while and I am writing to see how things are going with this issue. Have you had a chance to check the replies provided? Any update would be appreciated. 

Please feel free to let me know if there’s anything I can assist you with. 

I look forward to hearing from you soon.

Wish you have a great day. 

Best Regards,  
Viego An  - MSFT | Microsoft Community Support Specialist.

Answer 3

I spent about 6 hours trying to fix this. In the end ChatGPT offered me (after a few hours of failed attempts), the following suggestions:

Most Likely Root Causes Now

At this point, the error is being triggered by:

1. A corrupt or incompatible VBA component (e.g. outdated MSVBVM60.dll or VBE7.dll)
2. A damaged Office VBA runtime registry key
3. A third-party add-in or anti-virus blocking Solver code
4. A broken Excel template (XLSTART) or VBA project cache

---

✅ The Final Fix Path (guaranteed effective)

🔧 Step 1: Fully Reset Excel's VBA Runtime Cache

1. Close Excel completely
2. Open the following folder:

pgsql

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C:\Users\

1. Delete all files ending in .exd:

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MSForms.exd

Solver.exd

VBE6.exd

These are compiled binary caches of VBA references. If not cleared, they keep loading broken modules even from clean .xlam files.

---

📁 Step 2: Delete all Excel startup files (XLSTART)

Go to:

makefile

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C:\Users\

Move (don’t delete yet) any files like:

• PERSONAL.XLSB
• Book.xltx
• Anything .xlam, .xlsm, or .xlsb

These can silently auto-load macros that conflict with Solver.

---

🔐 Step 3: Turn off all third-party add-ins

1. Open Excel
2. File > Options > Add-ins
3. Bottom: Manage: COM Add-ins > Go
4. Uncheck everything
5. Repeat for Excel Add-ins > Go — leave only Solver Add-in

Some corporate add-ins or PDF printers inject VBA code into startup.

---

🧩 Step 4: Re-register Excel's VBA Components

This is key if your machine's VBA libraries are corrupted or mismatched.

Run these commands in Command Prompt (as Admin):

cmd

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regsvr32.exe /u "C:\Program Files\Common Files\Microsoft Shared\VBA\VBA7.1\VBE7.dll"

regsvr32.exe /u "C:\Windows\SysWOW64\mscomctl.ocx"

regsvr32.exe "C:\Program Files\Common Files\Microsoft Shared\VBA\VBA7.1\VBE7.dll"

regsvr32.exe "C:\Windows\SysWOW64\mscomctl.ocx"

If any of the paths don’t exist, skip that line.

This unregisters and re-registers VBA controls like the ones Solver depends on.

---

🛠 Optional but Effective: Use Excel’s /safe and /regserver flags

Try running Excel from command line like this:

c

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excel /safe

If Solver loads with no error, the issue is with another component — not Solver itself.

Then:

cmd

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excel /regserver

This command resets Excel's COM and registry mappings to their default — and often clears hidden add-in problems.

---

🧪 Final Clean Test

Now:

1. Open Excel
2. File > Options > Add-ins > Go
3. Re-enable Solver Add-in from:

makefile

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C:\Program Files\Microsoft Office\root\Office16\Library\SOLVER\Solver.xlam

1. Open VBA Editor (Alt+F11)
   Tools > References → Verify Solver is checked, not marked MISSING

Run test code:

vba

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Sub FinalSolverTest()

    SolverReset

    MsgBox "Success"

End Sub

---

✅ Summary of Deep Fix Actions

Step	Purpose
Delete .EXD files	Remove compiled cache of broken modules
Clear XLSTART	Stop hidden workbooks from loading Solver
Disable all COM add-ins	Prevent interference
Re-register VBA DLLs	Fix broken SolverCode runtime
Run excel /regserver	Fully reset Excel-VBA integration
Re-enable Solver manually	Final check

---

📌 Last Resort (Unusual Case)

If none of this works, it's possible the problem is:

• System-wide VBA corruption (would affect other Office apps too)
• A third-party antivirus blocking Solver macro code (esp. TrendMicro, McAfee, Sophos)

In that case, you can try:

• Creating a new Windows user profile and test there
• Or reinstalling Office in a fresh Windows user profile

---

It worked!!!!!!

🎉 YES! That's fantastic news! I'm really glad it finally worked — that was a tough one. You've just successfully beaten one of the hardest Excel errors to fix. 💪

Just to recap — what finally solved it for your setup was:

✅ Replacing Solver.xlam with a clean copy
✅ Clearing .exd files (compiled VBA cache)
✅ Disabling startup files and third-party add-ins
✅ Re-registering the VBA runtime components via regsvr32
✅ Running excel /regserver to fully reset Excel's COM mappings

It actually worked!!!!!!