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
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- Official documentation (searchable and regularly updated)
- How to topics and FAQs
- Forum search
(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):
32.0.2rc2-ls153
- Operating system and version (e.g., Ubuntu 24.04):
Windows 11 Pro
- Web server and version (e.g, Apache 2.4.25):
Unsure
- Reverse proxy and version _(e.g. nginx 1.27.2)
- Caddy 2.10.2-alpine
- PHP version (e.g, 8.3):
Unsure
- Is this the first time you’ve seen this error? (Yes / No):
Yes, new install/user
- When did this problem seem to first start?
Not been able to install yet
- Installation method (e.g. AlO, NCP, Bare Metal/Archive, etc.)
Docker
- Are you using CloudfIare, mod_security, or similar? (Yes / No)
Cloudflare for DDNS only
Summary of the issue you are facing:
I’ve attempted a new install, below I’ve included a link to a pastebin file with my docker-compose file. My knowledge of Linux is very weak, I tried to get by with ChatGPT with little success.
I’m using the developer build as the latest build doesn’t work with the latest version of Docker.
I’ve got the domain working, caddy too and can see the Nextcloud login page but after populating the details I see “Internal Server Error” and “The server was unable to complete your request”.
When I retry, it tells me the login is already used so it appears to be saving something.
Is there something wrong in my compose file? Note that Docker is installed in the C:\Docker directory but I want NextCloud storing it’s data on my D:\ drive.
Note the username and password are just for my testing, when I can get a proof of concept working my plan is to re-do the compose file and set up with proper values.
Content from docker-compose file.
Thank you in advance for any support, I have read various documentation and tried a variety of things - this is the furthest I’ve got and struggling.