Android app login issues for specific user

[JiroMusik]

Prerequisites

• I have searched the existing Closed AND Open Issues AND Discussions
• I have searched and read the documentation

Vaultwarden Support String

Hi guys, I am not sure if my current issue has to do with this (new device registration awaits SMTP #5856) but let me explain:

I was using the (always latest) Bitwarden App fine with my self-hosted Vaultwarden, which was some older version.
Today I tried to create an App that communicates via API to store secret notes. After some trial and error I got the connection to work but realized I used my personal API Key instead of the organization one.
After the first successful login of my new server-app - my Android App stopped working and only shows "unable to process your request".

I can login to the Bitwarden Web Clients and the normal Web GUI with this account and also I can login with other accounts on my android app and see their contents just fine. But my own user is not accessible via App. I rotated all secrets and KDF but nothing worked.

Of course I restarted the server (and later also updated it to 1.35.2) and deleted the Android App multiple times. I still can see the "android" in my "Apps" View on the Web Interface but can not delete it from there. I also disabled the 2FA for the account but also no success

I think it is seen as a new device and could be connected to #5856

Vaultwarden Build Version

1.35.2

Deployment method

Official Container Image

Custom deployment method

Synology NAS Container Manager (docker-compose)

Reverse Proxy

none

Host/Server Operating System

NAS/SAN

Operating System Version

Synology DSM 7.2

Clients

Android

Client Version

2025.12.1(21060)

Steps To Reproduce

Trying to Login with my usual account - Enter Masterpassword - see error

Expected Result

Showing my Vault

Actual Result

Showing error
Sync is possible, under Settings I can see the folders. But the Main "Vault" Tab in the App shows the error.
Proof for sync: Changing the "profile picture color" syncs to my phone!

Logs

<tr><th>date</th><th>stream</th><th>content</th></tr>
<tr><td>2026/01/16&nbsp;00:06:23</td><td>stdout</td><td>[2026-01-16&nbsp;00:06:23.167][response][INFO]&nbsp;(sync)&nbsp;GET&nbsp;/api/sync?&lt;data..&gt;&nbsp;=&gt;&nbsp;200&nbsp;OK
</td></tr>
<tr><td>2026/01/16&nbsp;00:06:23</td><td>stdout</td><td>[2026-01-16&nbsp;00:06:23.101][request][INFO]&nbsp;GET&nbsp;/api/sync
</td></tr>
<tr><td>2026/01/16&nbsp;00:05:25</td><td>stdout</td><td>[2026-01-16&nbsp;00:05:25.685][response][INFO]&nbsp;(sync)&nbsp;GET&nbsp;/api/sync?&lt;data..&gt;&nbsp;=&gt;&nbsp;200&nbsp;OK
</td></tr>
<tr><td>2026/01/16&nbsp;00:05:25</td><td>stdout</td><td>[2026-01-16&nbsp;00:05:25.324][request][INFO]&nbsp;GET&nbsp;/api/sync
</td></tr>
<tr><td>2026/01/16&nbsp;00:02:48</td><td>stdout</td><td>[2026-01-16&nbsp;00:02:48.903][response][INFO]&nbsp;(sync)&nbsp;GET&nbsp;/api/sync?&lt;data..&gt;&nbsp;=&gt;&nbsp;200&nbsp;OK
</td></tr>
<tr><td>2026/01/16&nbsp;00:02:48</td><td>stdout</td><td>[2026-01-16&nbsp;00:02:48.290][request][INFO]&nbsp;GET&nbsp;/api/sync
</td></tr>
<tr><td>2026/01/16&nbsp;00:02:48</td><td>stdout</td><td>[2026-01-16&nbsp;00:02:48.275][response][INFO]&nbsp;(put_device_token)&nbsp;PUT&nbsp;/api/devices/identifier/&lt;device_id&gt;/token&nbsp;=&gt;&nbsp;200&nbsp;OK
</td></tr>
<tr><td>2026/01/16&nbsp;00:02:48</td><td>stdout</td><td>[2026-01-16&nbsp;00:02:48.272][request][INFO]&nbsp;PUT&nbsp;/api/devices/identifier/9682a365-2c5e-408d-91de-46485fb51bdd/token
</td></tr>

Screenshots or Videos

No response

Additional Context

Do I just need to rotate the main encryption code (master key tab) like explained here?
https://bitwarden.com/help/account-encryption-key/#rotate-your-encryption-key

I just did the other two rotation options (keys tab)

[overlord-303]

A related issue with more information was also published in the official Bitwarden Android Repo: bitwarden/android#6363

[JiroMusik]

Yeah it seems to be this - somewhere I had exactly this seen in my logs.

So what to do since this is not handled as a bug here? There is no Vaultwarden android client - how would I be supposed to connect now? Or will the change in the original server be implemented in the vaultwarden server soon?

[stefan0xC]

Yeah it seems to be this - somewhere I had exactly this seen in my logs.

In your report above you have not mentioned that issue. Also this has already been added in #6572 so while possible I currently doubt that this is the same issue. You can of course provide more information and logs as well as the requested support string if the same error message still occurs even after upgrading.

[JiroMusik]

I totally forgot that I had seen this error but only for one time - I think after app reinstallation:

This is what I sent to Claude yesterday to look for possible fixes:

MissingPropertyException: Missing the required
MasterPasswordUnlock data property

[stefan0xC]

@JiroMusik You can delete all devices for a user in the Vaultwarden Admin panel by deauthorizing a user's sessions.

vaultwarden/src/api/admin.rs

Line 474 in b2cd556

Device::delete_all_by_user(&user.uuid, &conn).await?;

I was using the (always latest) Bitwarden App fine with my self-hosted Vaultwarden, which was some older version. Today I tried to create an App that communicates via API to store secret notes. After some trial and error I got the connection to work but realized I used my personal API Key instead of the organization one. After the first successful login of my new server-app - my Android App stopped working and only shows "unable to process your request".

So did your creation change anything? If so, what? And did you increase the note size limit?

vaultwarden/.env.template

Lines 463 to 467 in b2cd556

	## Increase secure note size limit (Know the risks!)
	## Sets the secure note size limit to 100_000 instead of the default 10_000.
	## WARNING: This could cause issues with clients. Also exports will not work on Bitwarden servers!
	## KNOW WHAT YOU ARE DOING!
	# INCREASE_NOTE_SIZE_LIMIT=false

[JiroMusik]

No, it was just the login and the request via API - no changes in the server configuration.

But with the sessions - yeah I did that and it seems to be the new sessions that show up - but the unlock fails obviously

[stefan0xC]

I'm still not sure what your app did. And what exactly do you mean by "request via API"? Did you store a note with your app or not?

[JiroMusik]

Yes correct, I logged in and stored a note. The note was visible in my vault. So far everything looked good until I opened the app on my phone.

[ecesarini]

Same here,
2 Android users got unable to process your request after submitting master password in Android app v2025.12.1: however server logs say User xxxxx@yyy.zzz logged in successfully during the attempt.
We're running vaultwarden 1.34.3 and everything worked fine for Android <= v2025.12.0

[BlackDex]

I would suggest the users to read this https://github.com/dani-garcia/vaultwarden/wiki/Bitwarden-clients-troubleshooting#tips-and-tricks-to-test-clients

And try the flight recorder feature.
That should provide more details

[Narrat]

Had the same error message with bitwarden client 2025.12.1 and vaultwarden 1.35.2

Stacktrace:
com.bitwarden.core.data.repository.error.MissingPropertyException: Missing the required MasterPasswordUnlock data property

I could resolve it with logging out the user from the app from the options menu where it asks for the master password to unlock and log in anew.

[t0xicCode]

Had the same error message with bitwarden client 2025.12.1 and vaultwarden 1.35.2

Stacktrace:
com.bitwarden.core.data.repository.error.MissingPropertyException: Missing the required MasterPasswordUnlock data property

I could resolve it with logging out the user from the app from the options menu where it asks for the master password to unlock and log in anew.

Same error here. Happy to provide logs/stack trace before I log out the user and re-log in

[voruti]

I could resolve it with logging out the user from the app from the options menu where it asks for the master password to unlock and log in anew.

I let the affected user reinstall the app (which implies logging-in anew) and that fixed it. Thanks!

[BlackDex]

Yea, sometimes the cache of the app causes strange issues. I know this happens with official Bitwarden servers too.

[wildex999]

Was on quite an old Vaultwarden version, 1.33.1 I think, and suddenly startet getting this error message when trying to open the vault on my android Bitwarden app.

Tried going into offline mode, but it would still instantly give the "unable to process your request" error.
Restarting the app did not work.
Updated to the latest Vaultwarden, 1.35.2, and tried again after re-starting the android app, but it would still instantly fail.

What fixed it for me was:

• Update to latest Vaultwarden.
• Log out completely on the Android app, and log back in again.

[JiroMusik]

I needed to recycle all of the keys and encryptions via Dashboard and was able to login again