I am working with a 67-page document, and it has just stopped me from
creating bullet points by selecting the text or the whole line and clicking
the bullets icon. The only way I can do this is by having the cursor on the
line, clicking the icon and moving the icon to the next line to bullet.

Also, it will no longer let me delete certain carriage returns (Enters)
using delete alone - I have to select the whole carriage return symbol in
order to delete it.

Does anyone have any idea what may be causing this and how to rectify it?

Many Thanks