how to set document viewer as default for pdf?

[milton]

Hi,

I use Ubuntu 22.04 with Orca master. Document viewer was was set default 
to open pdf-iles. All of a sudden this had dchanged to Image Magic Color 
which is not accessible with Orca. I tried the following without success:

1. right click on a pdf file and select Properties.

2. go to the tab OPEN WITH and select in the list Document viewer.

3. tab to the button default and press Enter.

Any help is appreciated.

Thanks in advance.

Milton