Hi Milayo,
If you see the lower section of the Theme Options Manager you will see a button to export the settings:

Click on that button and wait for a moment, then your browser will download a file with the name of: YOURWEBSITENAME-xcs.json
Save that file for the future to upload later. Please consider that you need to make sure you have the version 6.1.6 of the Theme and version 3.1.6 of the Cornerstone plugin to do that.
I double checked the link you gave us which is the event page and I also do see the error 500. I am sorry but it seems your hosting service support did not do a good job. They clearly should give you the error log to see what is the actual problem. The error 500 is not the actual problem, the host manager should check the error log and give you the actual one.
Thank you.