Troubleshooting - Applanix POSPac Software License Utility: Error 1001

📌 Problem

When attempting to install Applanix Software License Utility the user receives the following error message: 

Error 1001. Failed to decrypt using provider 'DPAPIProtection'. Error message from provider: Key not valid for use in specified state................

• The error is related to DPAPI (Data Protection API), which Windows uses for encrypting/decrypting sensitive data.
• The message Key not valid for use in specified state usually indicates:
  • The encryption key used to protect some configuration data cannot be decrypted in the current environment.
  • This often happens if the encrypted data was created under a different Windows user account or machine.

🧠Root Causes

1. User Account Change: The software was installed or configured under a different Windows user account.
2. Machine Change: The configuration file was copied from another computer.
3. Corrupted Configuration: The Applanix.SoftwareLicenseUtility.exe.config file contains encrypted values that cannot be decrypted.

✅ Probable Resolutions

1. Run Installer as Administrator

• Right-click the installer and select Run as administrator.

2. Delete/Recreate Config File

• Navigate to:     C:\ProgramData\Applanix\
• Locate Applanix.SoftwareLicenseUtility.exe.config.
• Rename or delete it, then reinstall the software. This forces the installer to create a fresh config.

3. Ensure Same User Account

• If you previously installed under a different account, log in with that account or reinstall under the current account.

4. Check DPAPI State

• If the machine was restored from backup or domain settings changed, DPAPI keys may be invalid. A full reinstall often resolves this.
  

✅Here’s a step-by-step guide to completely reset the installation and fix the DPAPI error:

Step 1: Uninstall POSPac SLU Completely

1. Open Control Panel → Programs and Features.
2. Locate Applanix POSPac SLU and click Uninstall.
3. After uninstalling, check these folders and delete any remaining files:
   • C:\Program Files\Applanix\
   • C:\ProgramData\Applanix\ (this is where the problematic config file resides)
4. Empty the Recycle Bin.

Step 2: Remove Corrupted Config File

• Navigate to:     C:\ProgramData\Applanix\
• Delete Applanix.SoftwareLicenseUtility.exe.config.
• If you cannot find it, ensure hidden files are visible:
  • In File Explorer → View → Show → Hidden items.

Step 3: Clean Registry Entries

1. Press Win + R, type regedit, and press Enter.
2. Navigate to: HKEYLOCALMACHINE\SOFTWARE\Applanix and HKEYCURRENTUSER\SOFTWARE\Applanix
3. Delete any keys related to Applanix POSPac SLU.(Be careful—only delete Applanix-related keys.)

Step 4: Restart Your Computer

• This ensures all cached settings are cleared.

Step 5: Reinstall POSPac SLU

1. Download the latest installer from Applanix official site.
2. Right-click the installer → Run as Administrator.
3. During installation, ensure you are logged in with the same Windows account that will run the software.

Step 6: Verify DPAPI State

• If the error persists, it may be due to a corrupted Windows DPAPI key store.
• Run this command in Command Prompt (Admin): certutil -user -repairstore my *(This repairs user certificate store, which DPAPI relies on.)

📬 Need Help?

If you're still stuck, please Contact Support for assistance.