My files got corrupted\encrypted for no reason on linux brfs file system, all my data is lost. Pls help

ℹ️ Support
1
Support intro

Installed nextcloud client on my linux machine with btrfs file system, and all my files got corrupted\encrypted. All I see now is ```
HBEGIN:oc_encryption_module:OC_DEFAULT_MODULE:cipher:AES-256-CTR:signed:true:encoding:binary:HEND

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. :heart:

The Basics

  • Nextcloud Server version (e.g., 29.x.x):
    nextcloud desktop client version 3.16.4daily (Arch)

  • Operating system and version (e.g., Ubuntu 24.04):
    Arch Linux 6.14.6-arch1-1

  • Is this the first time you’ve seen this error? (Yes / No):
    YES

  • When did this problem seem to first start?
    Couple of days ago

  • Installation method (e.g. AlO, NCP, Bare Metal/Archive, etc.)
    regular pacman install and use via hyprland exec-once commands and autostart settings

  • Are you using CloudfIare, mod_security, or similar? (Yes / No)
    NO

Summary of the issue you are facing:

Installed nextcloud client on my linux machine with btrfs file system, and all my files got corrupted\encrypted. All I see now is ```
HBEGIN:oc_encryption_module:OC_DEFAULT_MODULE:cipher:AES-256-CTR:signed:true:encoding:binary:HEND


### Steps to replicate it (hint: details matter!):

1. Install arch on a btrfs filesystem
2. Install nextcloud client, start using it
3. Witness how files become corrupted randomly

### Log entries

#### Nextcloud

How do i access Administration settings->Logging? 
nextcloudsync.log is empty...
2

These are server-side encrypted files. So the issue is something server-side. You’ll need to provide more details about your Nextcloud Server.

3

Just wanted to share a data point from a similar setup, since I also run Nextcloud extensively on Linux.

I’m using CachyOS (Arch-based) on three different devices — one with the xfs filesystem and two with btrfs.

The Nextcloud Desktop Client version 6.14 is installed from the CachyOS repositories, which directly mirror the official Arch Linux packages.

There is no encryption enabled on server-side.

My server runs Nextcloud AIO v10.14.0 (Hub 9) with Nextcloud version 30.0.10,
on Ubuntu Server 24.04.

I’ve been using this setup for over three years now, and I can confirm that synchronization works flawlessly across all devices, including those with btrfs.
I’ve never experienced any issues with data corruption or file loss.

4

It’s great to hear there were no problems with your setup. I use ordinary free official web server from nextcloud, the one that offers 8gb of storage space.

And I encountered this problem for the first time in my years of using nextcloud on different devices.

Usually, I would just download nextcloud client, enter my nextcloud url and then enter my login and a password and it synchronizes all the files up and I don’t even use nextcloud for custom data servers.

I generally use it as a sort of a substitute to google drive to store different settings and templates for apps and documentation and etc.

Unfortunately, this time around, all my files that were stored on nextcloud’s official server are corrupted\encrypted, and I can’t do anything with them. I have zero clue what to do at this point to restore them, it’s a good thing that I had a laptop that wasn’t connected to internet for quite a while, but it still has old data backed up on it.

This time around I just installed nextcloud via sudo pacman -S nextcloud nextcloud-client and thought that everything worked fine upon logging in. File manager showed that all the files are there. It took me a day working and tinkering with my arch setup until I started copying and using files on my nextcloud drive\server and to my horror discovered that all the files are corrupted\encrypted? despite having proper names and extensions and previews.

I’d really appreciate if somebody could tell me what could be done (I don’t have experience with encrypted files or setting up any encryption as well, neither did I go beyond checking standard settings in nextcloud gui). What kind of cli commands I could use to fix the problem or provide more details? You’d have to excuse my newbieness, I’m not that experienced with linux cli\bash as of now and would appreciate any help.

5

You’ll have to elaborate. Who is your actual provider?

I believe one provider (Tab) recently had some sort of issue where they encrypted files accidentally or something:

6

Hi! Thanks for replying! I just use https://mark.nl.tab.digital . I used it since like I installed nextcloud as an app, I think it was something set up by default, I’ve been using it ever since. I didn’t know there are different server providers XD.

7

A few quick suggestions to help narrow it down:

  • Try downloading the affected files directly via the web interface — do they open normally?
  • If you have SSH access to the server, try downloading files with rsync to rule out client-side corruption.
  • Also try using the AppImage version of the Nextcloud desktop client instead of the system package — see if it behaves differently.

This should help determine whether the issue is on the client or server side.