Error Message: Invalid Class

How to get the software running on your computer. Creating and configuring your portfolio file(s).
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Joined: Tue May 23, 2023 2:57 pm

Error Message: Invalid Class

Post by Darryl129 »

I had been using Moneylender 3 for several years, but I had not logged on since Feb 2023; when I went to go in and post payments for the last couple months, I received this error message and nothing I do seems to correct it. Only antivirus software I have on desktop is Windows Security.

Moneylender was unable to create a serial number for your computer.

Sometimes this happens if an anti-virus program is scanning Moneylender while it's trying to get the hardware serial numbers for your CPU and disk drives.

Sometimes it's because the Windows account you're using to run Moneylender doesn't have the privileges to access the computer's hardware configuration.

If the problem continues, try adding Moneylender to your anti-virus's whitelist and/or running Moneylender as Administrator. Moneylender will start in Demo mode.

Error message: Invalid class

The program does not start in Demo mode. The app is already "allowed" in Windows Security.

What should I do? Thanks.
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Re: Error Message: Invalid Class

Post by wtech_josh »

Somebody called with this problem six or twelve months ago. Windows keeps a list of all the properties of the hardware in your computer. If the property file gets corrupted somehow, Moneylender asks Windows about the connected disks and CPU and Windows returns this error when it encounters the corruption in the properties file.

I searched on Google for this error and found some step-by-step solutions. I followed one and was able to revert the properties file to a valid version and then Moneylender could verify the license without crashing.

Go to Start > Run > type "WMIMGMT.MSC" and press enter. Right click on WMI Control and choose Properties. On the General tab, you'll see an error with the same "Invalid class" message that Windows is giving to Moneylender.

I'm pretty sure we got it fixed by doing a Restore from the Backup/Restore tab with a file that had a suspicious name like "bad" or "old" but somehow worked just fine??

Steps to troubleshoot and fix on a windows support website: ... windows-10

Steps to correct on Stack Overflow:

Feel free to call the number on the Contact page of the website if you want help getting Moneylender working again.
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