Can't open doc file in Libreoffice: this file is from an unidentified developer I want to open a doc (word) file which is created on a Windows computer about 10 years ago. When I open this file I get the following message:

"Test12345.doc" is from an unidentified developer. Are you sure you want to open it? Openining "Test12345.doc" will always allow it to run on this Mac. 



At first Pages opened this file. I never use Pages, have always set Libreoffice to handle Word files including doc, but apparantly Apple found it necessary to overwrite this setting. So after opening this in Pages, then closing it, and trying to open it in Libreoffice and resetting LO as default application for doc files, this happens.

When I open the file info now, Libreoffice is set as default app for opening doc files, and it shows that I have read and write access for the file. 

Why do I get this message? I don't want to open an application, I want to open a document? What causes this?
Select the file in the Finder. 
Press CMD-I to open the info window.
Find the "Open with" part, and click the triangle to open it if it's not open already.
Click the dropdown menu, and choose "other", even if the preferred app is in the list.
Then find the right app, and check "always open with".
Then click the "change all" button.


Now it should work.