Depending on your A/V's definitions of problems... Some seem to flag even an off site URL as 'bad'. F U & D is the sales tactic for some (once decent).
Yep, I have been collecting user manuals for equipment I have (or was in the place I rented). So much easier to find when I need them.
BTW when in a books folder. Never change the name of any the files. (just delouse as needed)