Error Code:80029c4a Description:Error loading type library/DLL. When opening QuickBooks.

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In some cases, people opening the QuickBooks Pro, Premier, or Enterprise software are receiving the above error.

What’s happening?

This error typically occurs when 1 or more files for the program are damaged, or removed. This can occur when an anti-virus program mistakenly marks a file from the program as suspect.

Some users of Avast anti-virus began receiving this error after an update to the anti-virus mistakenly marked the DMUSERS.DLL file as suspect and quarantined the file.

If you are using Avast, Intuit recommends the following steps:

Exclude QuickBooks from the Live Monitoring Service:
note: your exact steps may differ depending on the version and level of Avast! anti-virus you have installed.

  1. Double click on the Avast! icon located in the system tray to launch the Avast! On-Access Scanner (next to the time in the lower right hand corner of the computer screen).
  2. Click Settings.
  3. Click the Antivirus option on the left-hand side.
  4. Scroll down to find the Exclusions section.
  5. Add the following file paths:
    • C:Program Files(x86)Common FilesIntuit
    • C:Program Files(x86)Intuit
    • If the company files are stored on the system’s hard drive (not a network drive) then add that directory as well.
  6. Click OK.

Restore files

  1. Double click on the Avast! icon located in the system tray to launch Avast.
  2. Click Scan(or Maintenance, depending on your version of Avast).
  3. Click Quarantine (Virus Chest).
  4. Right click the QuickBooks file that has been quarantined and select Restore and add to exclusions.
  5. Click Yes and then close the virus chest screen and Avast.

If you are using other anti-virus software, you will need to refer to their documentation to set them to ignore the QuickBooks software.

Even after configuring the anti-virus, you may still have issues and may need to perform a clean install to get the program operational.