Hello, I am very sorry for the massive bump. I am a IT technician for a university and I had received the exact same situation: .dotx would not open as a new document (only edit). I had spent several hours troubleshooting this ordeal, including all the techniques described on this thread. However, below is how I resolved the ordeal:

Who was impacted?

34 computers impacted with .dotx error with >300 unimpacted; 28 running Windows 10 Enterprise with Office 2019 ProPlus. Additionally, 6 running Windows 10 Education with a Office 365 A3 for students. All computers on Build 2004 64-bit, running 64-bit versions of Office products, and running Symantec Endpoint Protection for antivirus. 2 computers impacted had local administrator users with the rest lacking administrative access.

tl;dr Win10 with Office 2019 ProPlus + Win10 with O365.

How did you resolve your errorr?


1. Open Registry Editor with administrator

2. Open node "HKEY_CLASSES_ROOT"

3. Scroll down to find the file extension ".dotx"

4. Right click on ".dotx" and export the entire branch "HKEY_CLASSES_ROOT\.dotx"

5. Right click on ".dotx" and delete entire branch

Test the solution:
Double click on any '.dotx' file and see if it is a new document or not. You may have to reaffiliate .dotx with Office which can be done with Guessed's hyperlink: My docs open in the wrong program! Re-registering Word using the commandline.

I hope this helped for you. If it didn't, you can double click the previously exported ".reg" file to configure things to exactly how it was before deleting this directory.