A mysterious symbols appeared at the top of my desktop. Green arrow and clock.

robroper wrote:

A mysterious symbol appeared at the top of my desktop, it is a green arrow pointing down, going into a horizonal green line.

Is this it:

?

Apache Open Office update notification icon.

Green arrow pointing down icon?

Are you downloading anything from the web?

AirPlay icon?

https://support.apple.com/en-us/HT201343

You might try to take a screenshot of your desktop and share it here so we could help you:

How to take a screenshot on your Mac - Apple Support

The icon resembling a clock might just be... the clock.

As for the green downward pointing arrow, it reminds me of something that I can't place at the moment. Something I did not like though. Ascreenshotwould be most helpful.

To take a screenshot hold ⌘ Shift 4 to create a selection crosshair. Click and hold while you drag the crosshair over the area you wish to capture and then release the mouse button. You will hear a "camera shutter" sound. This will deposit a screenshot on your Desktop.

If you can't find it on your Desktop look in your Documents or Downloads folder.

When you post your response, click the "camera" icon above the text field:

This will display a dialog box which enables you to choose the screenshot file (remember it's on your Desktop) and click the Insert Image button.

⌘ Shift 4 and then pressing the space bar captures the frontmost window.

⌘ Shift 3 captures the entire screen.

(the use for ⌘ Shift 1 and 2 are trivia questions.)

Drag the screenshot to the Trash after you post your reply.

This is on Mac OS 10.10.3.

Update OS X. To learn how to do that read Update OS X and App Store apps on your Mac - Apple Support.

robroper wrote:

Yes, that's it. But it went away, not there anymore.

Then your copy of Open Office is up to date. It will return when you launch OO and an update is available.