Contributors cannot save

Since updating to V7.1 and fluid engine, when my site contributors duplicate or edit an event and hit save in the event settings dialog box a black rotating square appears where publish should be, (see screen capture). This also happens if you select BACK from the event settings and save on the main page. This never goes away and locks up the screen requiring them to exit the browser and log back in. The changes were saved but they must now publish as a separate edit step. Any additional edits requiring save repeat the problem. I do not have this problem as an admin but did create a contributor account for myself an have verified this happens.