"Reset" Button Deletes Data Unexpectedly

[miqrogroove]

Steps to reproduce

1. Create repeating appointment using aCalendar.
2. Edit appointment using ownCloud Calendar web app.
3. Click the Repeating tab.
4. It says Advanced data is not supported, so click the Reset button.

Expected behaviour

Appointment's repeat settings should be blanked out/editable.

Actual behaviour

Appointment is completely deleted with no undo or edit option.

Server configuration

Operating system: Ubuntu

Web server: Apache

Database:

PHP version:

ownCloud version: (see your admin page) 10.5.0.10

Calendar version: (see the apps page) 1.6.4

Updated from an older installed version or fresh install: Yes, updated months ago.

Signing status (ownCloud 9.0 and above): No errors have been found.

List of activated apps:

If you have access to your command line run e.g.:
sudo -u www-data php occ app:list
from within your instance's installation folder

ownCloud configuration:

If you have access to your command line run e.g.:
sudo -u www-data php occ config:list system
from within your instance's installation folder

or 

Insert your config.php content here
Make sure to remove all sensitive content such as passwords. (e.g. database password, passwordsalt, secret, smtp password, …)

Are you using external storage, if yes which one: smb

Are you using encryption: no

Are you using an external user-backend, if yes which one: No

### Client configuration
**Browser:** Chrome

**Operating system:** Windows

**CalDAV-clients:** CalDAV-Sync for Android

### Logs
#### Web server error log

Insert your webserver log here

#### Log file (data/owncloud.log)

Insert your ownCloud.log file here

#### Browser log

Insert your browser log here, this could for example include:

a) The javascript console log
b) The network log
c) ...