Cannot back up since PHP 8.0.0

I have the exactly same issue on dozens of websites.

0000.001 (0) UpdraftPlus WordPress backup plugin (https://updraftplus.com): 1.16.43 WP: 5.6 PHP: 8.0.0 (fpm-fcgi, Linux *censored by vlasi* 4.19.0-13-amd64 #1 SMP Debian 4.19.160-2 (2020-11-28) x86_64) MySQL: 10.3.27-MariaDB-0+deb10u1 WPLANG: cs_CZ Server: nginx/1.14.2 safe_mode: 0 max_execution_time: 500 memory_limit: 512M (used: 12M | 6M) multisite: N openssl: OpenSSL 1.1.1g  21 Apr 2020 mcrypt: N LANG:  ZipArchive::addFile: Y
0000.001 (0) Free space on disk containing Updraft's temporary directory: 107766.1 MB
0000.002 (0) Deleting old temporary file: backup_2020-12-22-2211_Main_WP_fea13184651f-plugins.zip.tmp
0000.007 (0) Tasks: Backup files: 1 (schedule: daily) Backup DB: 1 (schedule: daily)

End of log file… :/

Hi,

To help us find out the cause of the issue, please could you send us a copy of the full backup log? This can be found in the UpdraftPlus Existing Backups tab. The contents will be too long to post here directly, but you can use an online service such as Dropbox or Pastebin, and post the link here.

Regards,
Bryle

There are no existing files under this tab.

I think that I found the log file – here is the link – https://www.dropbox.com/s/giyfe5myejef0y8/log.txt?dl=0

Hi,

Could you try to reduce the backup archive split size. This will split the backup into smaller, more manageable files.

To do this, open the ‘expert settings’ section of the UpdraftPlus Settings tab, and find the ‘split backups every’ option. Set this to 25Mb save your settings and run a new process.

If the issue persists, please ask your hosts/server admin to investigate their PHP error logs. These logs should contain more information on the exact issue that is causing the backup process to halt.

Kind Regards,
Bryle

Splitting the backups did not work.

On the server-side (Apache) there is this error message that may help – [Tue Dec 29 10:28:09.874517 2020] [pagespeed:warn] [pid 24163:tid 139782785095552] [mod_pagespeed @24163] [1229/102809:WARNING:serf_url_async_fetcher.cc(1197)] Aborting fetch of https://www.swissmanda.com/wp-content/plugins/updraftplus/includes/images/ui-icons_ffd27a_256x240.png (connecting to:128.65.195.35:80)

What is in your PHP error log?