### ⚠️ Before submitting, please verify the following: ⚠️
- [X] This is a **b…ug**, not a question or a configuration issue.
- [X] This issue is **not** already reported on Github (I've searched it).
- [X] Nextcloud Server and Desktop Client are **up to date**. See [Server Maintenance and Release Schedule](https://github.com/nextcloud/server/wiki/Maintenance-and-Release-Schedule) and [Desktop Releases](https://nextcloud.com/install/#install-clients) for supported versions.
- [X] I agree to follow Nextcloud's [Code of Conduct](https://nextcloud.com/contribute/code-of-conduct/)
### Bug description
After updating to desktop client v3.8.0 I started to see strange sync issues. Encrypted changed and created files could not be synced with the server anymore.
- I thought "well, just that time of the year E2EE had its hiccups, just start over" and spent almost 4 hours in resetting E2EE.
- In the end it did fix nothing.
With v3.8.0 there are metadata issues. Clients give `Error with the metadata. Getting unexpected metadata format.`.
### Steps to reproduce
1. Start fresh with E2EE for a user by resetting E2EE (meta-data, private key, public key, potential file lock entries, corresponding filecache entries, delete all previously existing E2EE folders, run `occ files:scan-app-data` etc.)
2. Desktop client **with 3.8.0**: enable E2EE by setting a passphrase
3. Another client (I used the iOS app): clear E2EE from settings, supply same (new) passphrase as set in step 2
4. Desktop client: create a new empty folder and encrypt it, put one file in it
5. iOS client: try to access the encrypted folder
Note: you can also create the folder on the iOS client and try to access it from the desktop client, same result.
### Expected behavior
Access is possible as usual.
### Which files are affected by this bug
All E2EEncrypted!
### Operating system
Windows
### Which version of the operating system you are running.
Windows 10
### Package
Appimage
### Nextcloud Server version
25.0.5.1
### Nextcloud Desktop Client version
3.8.0
### Is this bug present after an update or on a fresh install?
Updated to a major version (ex. 3.3.6 to 3.4.0)
### Are you using the Nextcloud Server Encryption module?
Encryption is Enabled
### Are you using an external user-backend?
- [X] Default internal user-backend
- [ ] LDAP/ Active Directory
- [ ] SSO - SAML
- [ ] Other
### Nextcloud Server logs
```shell
This seems to be the initial issue (not fully sure):
{"reqId":"zCH6yCfRIeEVQuTq6QP7","level":3,"time":"2023-04-03T20:34:34+02:00","remoteAddr":"xxx.xxx.xxx.xxx","user":"Username","app":"no app in context","method":"DELETE","url":"/ocs/v2.php/apps/end_to_end_encryption/api/v1/lock/871525","message":"Intermediate meta-data file missing","userAgent":"Mozilla/5.0 (Windows) mirall/3.8.0stable-Win64 (build 20230331) (Nextcloud, windows-10.0.19045 ClientArchitecture: x86_64 OsArchitecture: x86_64)","version":"25.0.5.1","exception":{"Exception":"OCA\\EndToEndEncryption\\Exceptions\\MissingMetaDataException","Message":"Intermediate meta-data file missing","Code":0,"Trace":[{"file":"/var/www/nextcloud/apps/end_to_end_encryption/lib/Controller/LockingController.php","line":133,"function":"saveIntermediateFile","class":"OCA\\EndToEndEncryption\\MetaDataStorage","type":"->"},{"file":"/var/www/nextcloud/lib/private/AppFramework/Http/Dispatcher.php","line":225,"function":"unlockFolder","class":"OCA\\EndToEndEncryption\\Controller\\LockingController","type":"->"},{"file":"/var/www/nextcloud/lib/private/AppFramework/Http/Dispatcher.php","line":133,"function":"executeController","class":"OC\\AppFramework\\Http\\Dispatcher","type":"->"},{"file":"/var/www/nextcloud/lib/private/AppFramework/App.php","line":172,"function":"dispatch","class":"OC\\AppFramework\\Http\\Dispatcher","type":"->"},{"file":"/var/www/nextcloud/lib/private/Route/Router.php","line":298,"function":"main","class":"OC\\AppFramework\\App","type":"::"},{"file":"/var/www/nextcloud/ocs/v1.php","line":63,"function":"match","class":"OC\\Route\\Router","type":"->"},{"file":"/var/www/nextcloud/ocs/v2.php","line":23,"args":["/var/www/nextcloud/ocs/v1.php"],"function":"require_once"}],"File":"/var/www/nextcloud/apps/end_to_end_encryption/lib/MetaDataStorage.php","Line":174,"CustomMessage":"--"}}
Nothing in logs for the client messages "Error with the metadata. Getting unexpected metadata format." !!!
```
### Additional info
You should maybe have a look at what you did in e. g. (quick screening for E2E relevant changes)
- https://github.com/nextcloud/desktop/pull/5448
- https://github.com/nextcloud/desktop/pull/5534
- https://github.com/nextcloud/desktop/pull/5560
I downgraded to 3.7.4 and everything is working as expected/normal! No more sync issues or error messages. Just a bit of data loss and loss of 4 hours... thanks.
Currently in rage mode and not willing to upgrade to 3.8.0 again to provide desktop client logs. Sorry.