Support intro
Sorry to hear you’re facing problems. 
The community help forum (help.nextcloud.com) is for home and non-enterprise users. Support is provided by other community members on a best effort / “as available” basis. All of those responding are volunteering their time to help you.
If you’re using Nextcloud in a business/critical setting, paid and SLA-based support services can be accessed via portal.nextcloud.com where Nextcloud engineers can help ensure your business keeps running smoothly.
Getting help
In order to help you as efficiently (and quickly!) as possible, please fill in as much of the below requested information as you can.
Before clicking submit: Please check if your query is already addressed via the following resources:
(Utilizing these existing resources is typically faster. It also helps reduce the load on our generous volunteers while elevating the signal to noise ratio of the forums otherwise arising from the same queries being posted repeatedly).
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. 
The Basics
- Nextcloud Server version (e.g., 29.x.x):
- Version 31.0.2
- Operating system and version (e.g., Ubuntu 24.04):
- Android 8.0.0
- Are you using CloudfIare, mod_security, or similar? (Yes / No)
- No
Summary of the issue you are facing:
When I am trying to connect to the Nextcloud server in the Talk app, I get the error “HTTP 404” in the mask for the server address. I use other Nextcloud apps with the same address and don’t face any problems.
Log entries
Nextcloud
Please provide the log entries from your Nextcloud log that are generated during the time of problem (via the Copy raw option from Administration settings->Logging screen or from your nextcloud.log located in your data directory). Feel free to use a pastebin/gist service if necessary.
[webdav] Fehler: Validation error in iCalendar: RRULE MUST NOT appear more than once in a VTODO component
PUT /remote.php/dav/calendars/eschoe/hausarbeit/4D0F882D-5659-4661-84BA-096EFE456B5F.ics
von 2001:9e8:8802:3d00:27dc:c7e:53d7:7281 von eschoe um 08.07.2025, 15:52:17