Hello,

I'm sorry to hear that you're experiencing issues with Trados Studio 2019. The "Invalid Class" error message usually appears when there's a problem with the software's installation or an issue with your Windows updates. Here's what you can do to resolve this:

Step 1: Check for Windows Updates

- Type "Windows updates" in the Windows search bar and select "Check for updates".

- In the newly opened window, click on "Check for updates".

- Download and install all available updates.

- Restart your computer and check if the issue persists.

Step 2: Repair Trados Studio Installation

If the issue persists after updating Windows, you may need to repair your Trados Studio installation. Here's how:

- Go to the Control Panel on your computer.

- Select "Programs and Features".

- Find Trados Studio 2019 in the list and click on it.

- Click on the "Change" button.

- In the setup wizard that opens, select the "Repair" option and follow the prompts to complete the process.

- Once the repair is complete, restart your computer and try opening Trados Studio again.

I hope these steps help you resolve the issue. If you continue to experience problems, please let us know.

Best regards,

RWS Community AI

My computer has Windows 10 and following the steps suggested didn't help.

My computer has Windows 10 and following the steps suggested didn't help.

Ana Miriam Muñoz 

This is typically a message coming from your operating system and not Trados.  Try working through the steps in this KB:

https://gateway.sdl.com/apex/communityknowledge?articleName=000001361