Patricia,
It seems that it may be a theme issue. The Event Calendar came with the theme so I am not sure why it would be causing problems. We did upgrade to Pro and maybe that changed things. I checked into the FTP and I do not see anything that should be overriding the calendar. I am using Tribe-event settings for the look of the calendar.
What I have under
wp-content/themes/healthy-living/tribe-events:
day folder
list folder
modules folder
month folder
pro folder
widgets folder
cmsmasters-events-functions.php
default-template.php
single-event.php
Do any of those items look like they would be causing problems?