I get "%20" signs in file name when open attachments

[Guest]

when I open attachement in Excell the file name appears with these signs
before every word or number. Need help to get rid of it. Otherwise can not
save it until erase all junk out of the name.

 

[David Biddulph]

%20 is the symbol for a space.
Why can't you save?

 

[Guest]

This is correct that this is symbol for a space, but I do not want to have my
files saved with all those signs. It makes the file name too long and has all
this junk.
It started recently on my computer. I did not have it before. Any way to go
back to just space, without a symbol for a space?