"Can Not Find Item" and similar prompts

My apologies if this has been discussed (and hopefully solved) in the past.
Windows 8 FILE EXPLORER has begun prompting me that it "can't find" or items "do not exist" when I try to manipulate the files in any manner.
Of course they DO exist and oddly, if I repeat the command, the job gets done.

So...the functions seem to work, but I must repeat them and deal with this pesky prompt.

I am reluctant to use System Restore as I have made some time consuming changes to my OS since this problem started and do no suspect it will be successful.

scannow did not find any errors.

I use Firefox and am 64 bit.

Ideas?

ummm.... interesting issue but old... thought microsoft would give a fix for it in win8 but they didnt.... the problem deals with your file indexing..

go to start ,type indexing options , verify whether your file's extension is indexed in your PC or not , for more you could read this article... it actually is based on win7 but will work on win8 too

Windows 7 File Search Indexing Options - Help Desk Geek

Thank-you Salim96,
I have begun re-indexing and will report back

welcome dude juz don't forget to give a rep