The following solutions can be implemented in order to fix the error:

• Update the antivirus and antimalware programs on your system.
• Perform a full scan of the system once the program has been activated.
• Fix the bugs and eliminate the virus and malware, if any.
• In case, there is no virus and the problem persists, apply other solutions.

• Download and install the QuickBooks File Doctor application tool.
• Run the QuickBooks File Doctor and will diagnose and eliminate the error.

• Copy all the company related files to another system and check if they are opening in this system or not.
• If the file opens in this system, then it will be advised to repair the Windows on the system on which QuickBooks was initially installed.
• In case the files do not open in the new system also, then they are damaged. To repair the damaged files, use QuickBooks File Doctor Tool as mentioned in Solution 2.

• To uninstall QuickBooks, go to the Control Panel and select uninstall.
• Select QuickBooks and try to repair it when given the option.
• If the error still persists, then uninstall and reinstall the QuickBooks.

• Clean out the junk and trash files from your system.
• Repair the registry entries related to the error.
• Use Windows System Restore so that you can undo the recent changes in the system.

Hope this helps you out.

Method: Repair and reinstall QuickBooksTo begin, navigate to the Control Panel and select the Uninstall option.Then, pick QuickBooks and try to resolve the issue indicated in the choice.If you are still unable to resolve the problem, remove the QuickBooks programme and reinstall it.
Also Read: How to Void a Check in QuickBooks | Easy Methods

QuickBooks Error 4120 is an error code that typically occurs when there is an issue with the company file. It can be caused by various factors, such as damaged company files, incorrect installation of QuickBooks, or issues with the Windows operating system. Here are some steps you can take to troubleshoot and resolve QuickBooks Error 4120:

Update QuickBooks: Ensure that you have the latest updates for QuickBooks installed. Go to the Help menu within QuickBooks and select "Update QuickBooks." Follow the prompts to download and install any available updates.

Run QuickBooks File Doctor: QuickBooks File Doctor is a built-in diagnostic tool that can help resolve common company file issues. Open QuickBooks and go to the File menu. Select "Utilities" and then choose "Repair File and Network Problems." Follow the on-screen instructions to run the File Doctor.

Verify the company file: Open QuickBooks and go to the File menu. Select "Utilities" and then choose "Verify Data." This process will check for any data integrity issues within your company file. If any issues are detected, follow the prompts to resolve them.

Rebuild the company file: If the Verify Data process detects any issues, you may need to rebuild the company file. Go to the File menu in QuickBooks and select "Utilities." Choose "Rebuild Data" and follow the on-screen instructions. Note that this process may take some time, depending on the size of your company file.

Disable antivirus and firewall temporarily: Antivirus or firewall software can sometimes interfere with QuickBooks operations. Temporarily disable your antivirus and firewall, then try opening QuickBooks and accessing the company file again. If the error doesn't occur, you may need to adjust the settings of your security software to allow QuickBooks access.

Perform a clean install of QuickBooks: Uninstall QuickBooks from your computer and then reinstall it using a clean install process. This involves completely removing QuickBooks and its related files before reinstalling it. You can find detailed instructions for a clean install on the QuickBooks support website.

Regards,
Peter

Thank you for providing this solution for QuickBooks User. If you want QuickBooks Data Compression Services from experts than you should call on toll free number +1-(855)-955-1942