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Sorry to hear you’re facing problems 
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In order to help you as quickly as possible, before clicking Create Topic please provide as much of the below as you can. Feel free to use a pastebin service for logs, otherwise either indent short log examples with four spaces:
example
Or for longer, use three backticks above and below the code snippet:
longer
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Some or all of the below information will be requested if it isn’t supplied; for fastest response please provide as much as you can 
Nextcloud version eg, 18.0.2:
Operating system and version Ubuntu Linux 18.04.2 :
Apache or nginx version Apache version 2.4.29 nginx reverse proxy:
PHP version 7.2:
The issue you are facing:
My question is: Is the calendar and contacts sync a two way street. Is there a way to see my ios calendar in NC? As it stands I can create an event on my ios device and if I use the NC ‘Personal’ calendar I can see it in NC web interface. However, I cant see my ios calendar in NC.
Contacts: If I create it in NC, I can see it in both places. I don’t see any of my ios contacts in NC
Is there a way to force a sync?
Is this the first time you’ve seen this error? (Y/N): Y
The output of your Nextcloud log in Admin > Logging:
PASTE HERE
The output of your config.php file in /path/to/nextcloud (make sure you remove any identifiable information!):
PASTE HERE
The output of your Apache/nginx/system log in /var/log/____:
PASTE HERE