[READ BEFORE POSTING] What's required to diagnose a problem

rfc2822

If you have a problem with DAVx⁵, please:

Try the latest DAVx⁵ version. Use the latest version of your server software, if applicable.
Read the Configuration, FAQ and manual pages carefully. The most common issues are explained there.
Try the forum search – most questions have already been answered.
Have a look at the debug info/error details/logs. You can often get an idea what’s the problem yourself.
Search the the Web for the problem, maybe ask friends who are willing to help.
Make sure that it’s not a server or networking problem. Search the FAQ/forums/bug tracker of your server software, too. Many supposed DAVx⁵ bugs are server or networking problems.

When posting, please provide as much information as you can:

Go to DAVx⁵ / Settings (left navigation drawer in the main screen) / Debug info. Send these information to yourself (using the “Share” action, for instance by email). Paste the info to fpaste.org or a similar service and provide a link. It contains the most important information about your device and configuration.
Describe exactly what you were doing (steps to reproduce), what you tried to achieve and what your problem is. Imagine someone else who wants to reproduce the problem to find a solution and provide all necessary information.
Give information about your environment: what is your server software (including version), what are your calendar URLs, do other clients work, etc.
If possible, try to explain what you already have tried to solve your problem.

Additionally:

If you get “No CalDAV/CardDAV service found” when you try to add an account:

Tap “View logs”. Send those logs to yourself (using the “Share” action, for instance by email).
Paste the logs to fpaste.org or a similar service and provide a link (feel free to let it expire in a month).

If you get an error notification while synchronizing:

Tap the notification. A debug info activity will appear.
Send the debug info to yourself (using the “Share” action, for instance by email).
Paste the debug info (≠ logs) to fpaste.org or a similar service and provide a link (feel free to let it expire in a month). Short debug output can be inserted in the text, but please quote with ``` (at the beginning and the end).
If additional logs are required to diagnose the problem, continue below.

Your problem doesn’t cause a notification or you need verbose logs?

DAVx⁵ / Settings (left navigation drawer in the main screen) / Enable “Verbose logging”. A permanent notification tells you that logging is now active.
Do whatever causes your problem (e.g. “Refresh calendars”, or initiate a sync).
Use the notification to share the log. You may have to expand the notification to see the “Share” action.
Send the logs to yourself (for instance by by email, or with Share with HTTP).
Remove private data from the logs, if applicable.
Paste the logs to fpaste.org or a similar service and provide a link (feel free to let it expire in a month). Short parts of the logs can be inserted in the text, but please quote with ``` (at the beginning and the end).

Other hints:

If your problem has been solved, it would be kind to let other people (who were willing to help you) know the actual solution.