Why are some items greyed out?

EmmaWK

I was looking at one of my entries in Zotero, under which there are some notes and attachments. But some of them are greyed out. Why?

There are:
One attached note (not greyed out)
One link to an external application (greyed out)
Another link to the same external application (not greyed out)
Attached PDF stored with Zotero (greyed out)

I'm sorry if the answer is really obvious!

dstillman

Items that match the current search will be in black. Items that don’t will be gray.

EmmaWK

Thanks, it was indeed a simple answer! Just trying to make sure I didn't accidentally lose any files.