I'm running Windows 10 1607 (build 14393.105) and the Snipping Tool does NOT clear the clipboard on close.
Based on your explanation of the chain of events, I think I see what's going on.
- You copy TEXT to the clipboard.
- You then capture something with the Snipping Tool (which, by default automatically copies that IMAGE to the clipboard (replacing the text you copied previously).
- You then close the Snipping Tool and expect you can then paste your text, but you cannot, because it's been replaced by an image, which can't be pasted into the area you're trying to paste text. Since you can't paste an IMAGE to a TEXT area, it pastes nothing.
You can test this by opening Paint and the Snipping Tool, snipping an image, then closing the Snipping Tool, and then pasting it into Paint. It should still paste the image, even though the Snipping Tool is closed.
Something that may help:
There is a setting in the Snipping Tool's options entitled "Always copy snips to the Clipboard":
If you un-check that option, the image won't automatically be copied to the clipboard as soon as you snip it. Instead, you'll have to hit the "Copy" icon in the Snipping Tool: