Libre Writer : change default font to be on all my documents

I am new to Libre Office. I have experienced consistent and consecutive problems when saving my documents. I save them in ODF format, then close the document. When I go to open my documents at a later time, a box opens up instructing me to start the recovery process for the document. So I do. However, this does no good at all since this occurs repeatedly every time I open a document that was written and saved using Libre Office.

this appears to be 2 different issues. i don’t know what fonts you are using but if you select the whole document you can change its font. be aware however that this will also change any special characters from other fonts such as symbol & wingdings to the new font requiring you to go back & manually identify those characters & reinsert. i can’t help with the 2nd issue. gook luck keng