Server: Cannot modify header information Since NC19 RC2

[axheli]

Error | PHP | Cannot modify header information - headers already sent by (output started at /var/www/nextcloud/3rdparty/sabre/http/lib/Sapi.php:132) at /var/www/nextcloud/apps/dav/lib/Connector/Sabre/File.php#680
-- | -- | --

[Nils160988]

Can you use the issue template to make it easier to debug your issue?

[axheli]

I'm sorry about that.

Running Ubuntu 18.04 Server
PHP 7.3
apache2

[nextcloud-stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity and seems to be missing some essential information. It will be closed if no further activity occurs. Thank you for your contributions.

[axheli]

What is needed

[nextcloud-stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity and seems to be missing some essential information. It will be closed if no further activity occurs. Thank you for your contributions.

[Derkades]

I got a very similar error today:

Cannot modify header information - headers already sent by (output started at /var/www/html/3rdparty/sabre/http/lib/Sapi.php:132) at /var/www/html/apps/dav/lib/Connector/Sabre/File.php#683

Nextcloud 19.0.3, PHP 7.4 (fpm with nginx)

[Quiver92]

nextcloud.log
Hi! The same error:
Error: Cannot modify header information - headers already sent by (output started at /var/www/html/3rdparty/sabre/http/lib/Sapi.php:132) at /var/www/html/apps/dav/lib/Connector/Sabre/File.php#691

1. Share link Folder fo Upload
2. Go to shared link
3. Add file/Drag n Drop
4. On GUI screen appears: Could not upload""
5. In nextloud log's: Error: Cannot modify header information - headers already sent by (output started at /var/www/html/3rdparty/sabre/http/lib/Sapi.php:132) at /var/www/html/apps/dav/lib/Connector/Sabre/File.php#691
6. The above error appears 3 times
   

PHP: 7.4.11
DB: mysql 10.5.6
Nextcloud 20.0.2
Apache/2.4.41
Docker version 19.03.13

I'm using reverse proxy