Support intro
Sorry to hear you’re facing problems 
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In order to help you as quickly as possible, before clicking Create Topic please provide as much of the below as you can. Feel free to use a pastebin service for logs, otherwise either indent short log examples with four spaces:
example
Or for longer, use three backticks above and below the code snippet:
longer
example
here
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 
Some useful links to gather information about your Nextcloud Talk installation:
Information about Signaling server: /index.php/index.php/settings/admin/talk#signaling_server
Information about TURN server: /index.php/settings/admin/talk#turn_server
Information about STUN server: /index.php/settings/admin/talk#stun_server
Nextcloud version (eg, 24.0.1): 33.0.4
Talk Server version (eg, 14.0.2): 23.0.5
Custom Signaling server configured: no
Custom TURN server configured: yes
Custom STUN server configured: yes
In case the web version of Nextcloud Talk is involved:
Operating system (eg, Windows/Ubuntu/…): Ubuntu 24.04.4 LTS
Browser name and version (eg, Chrome v101): Firefox latest
The issue you are facing:
When I sent any messages from talk i got the error:
Could not post message: Request failed with status code 500
My messages were still sent but no push notifications were working. This was right afetr a 33.0.4 update.
I ended up modifying :
sudo vim /var/www/nextcloud/apps/notifications/lib/Push.php
$appConfig = $this->appConfig;
$paddingSetting = ($appConfig !== null) ? $appConfig->getAppValueString('push_encryption_padding', 'PKCS1') : 'PKCS1';
$padding = $paddingSetting === 'OAEP' ? OPENSSL_PKCS1_OAEP_PADDING : OPENSSL_PKCS1_PADDING;
// $padding = $this->appConfig->getAppValueString('push_encryption_padding', 'PKCS1') === 'OAEP' ? OPENSSL_PKCS1_OAEP_PADDING : OPENSSL_PKCS1_PADDING;
if (!openssl_public_encrypt(json_encode($data), $encryptedSubject, $device['devicepublickey'], $padding)) {
And restarted php-fpm and I am good.
This is just a heads up for anyone with this issue. I am not sure I am putting the issue in the right place.
Happy Friday.