I have read the File Share User Manual and have seen both the circular green arrows and the red exclamation point, but can't determine the difference.
For example, Pam made a change to a file after checking it out then checking it back in. The way I read the manual, when this happens, I should see the green circular arrows. However, I saw the red exclamation point.
The green arrows indicate that you have an older version of the file than the current version in File Share. The red exclamation mark indicates that you have a different version than is (does not match any) in File Share, including any of the various revisions. Another way to think about the red exclamation is that you changed the file on your computer and never checked in those changes... Regardless of how many times someone else changes that file, your version is never going to match the one that is in File Share = red exclamation mark.
When you have the red exclamation you need to make a decision -- do I want to check in my new version, or do I want to download the version from File Share? This depends, of course, on the file and what changes you've made. If you want to upload your changes, right-click on the file and choose "Check Out", then right-click the file and choose "Check In". The Check Out function puts a lock next to the file to indicate to other that you have it checked out and no one should make changes until you check your changes back in; in fact, they won't be able to check in a new version of the file until you check in or unlock it. The Check In function is what actually uploads your version of the file to the server so that others can see it -- before you do Check In, none of your changes are available to other users. If you just want to get the latest version from the server, overwriting your version, you would right-click on the file and choose "Get Latest".
Sometimes you won't know what the proper course of action is since you don't know who changed what. To help you decide, right-click on the file and choose "Properties". Now click on the "Revision" tab to see a list of the various revisions that have been checked in. Here is where that note that you enter when you check in a file comes in -- the note should indicate what was changed so that you can decide what to do. In some cases, you may want to pull out a previous revision of the file, right-click on the revision you want and choose "Get Revision" to download that version of the file. Whenever you download a version it overwrites whatever version you have already, so you may want to check in any changes you have made before doing this.
There is only one exception to how the indicators work that I know of. When you open an Excel file, Excel changes the contents of the file whether of not you purposely save any changes. What this means is that your Excel files will always indicate a different version -- red exclamation mark -- after opening the file, whether or not you saved changes to the file. This makes Excel files a little confusing at times, but there isn't anything we can do about that, besides checking in the file to make sure that the most recent version is uploaded.
As a general practice when using File Share, what you want to do is Check Out a file any time you are updating, or think you might update it. When you are done, Check In the file to upload and unlock the file. Not Checking Out, or leaving un-Checked In revisions on your computer is when you have the possibility of someone else changing the file at the same time as you, creating two unrelated versions of the file.