Hi, I’ve tried several backups without success.
With another very similar website I had no trouble..
Any help would be greatly appreciated, Thank you!

Hello @duongcuong96
Thank you for your attention. I have uninstalled the plugin and installed it again, but no improvement..Still getting same errors.
I don’t know where to look for the backwpup-dfa0ca-temp folder?

see log:
[INFO] BackWPup 3.8.0; A project of Inpsyde GmbH
[INFO] WordPress 5.5.3 on https://www.tuscanyballooning.com/wordpress/
[INFO] Log Level: Normal
[INFO] BackWPup job: backup1 TB.com
[INFO] Logfile is: backwpup_log_a42b21_2020-12-01_18-49-18.html
[INFO] Backup file is: 2020-12-01_18-49-18_DF47RAVO01.tar.gz
[01-Dec-2020 18:49:18] 1. Try to backup database …
[01-Dec-2020 18:49:18] Connected to database Sql623090_2 on 62.149.150.178
[01-Dec-2020 18:49:22] Added database dump “Sql623090_2.sql.gz” with 5.50 MB to backup file list
[01-Dec-2020 18:49:22] Database backup done!
[01-Dec-2020 18:49:25] 1. Trying to make a list of folders to back up …
[01-Dec-2020 18:50:28] Added “wp-config.php” to backup file list
[01-Dec-2020 18:50:28] 7055 folders to backup.
[01-Dec-2020 18:50:28] 1. Trying to generate a file with installed plugin names …
[01-Dec-2020 18:50:28] WARNING: fopen(compress.zlib:///web/htdocs/www.tuscanyballooning.com/home/wordpress/wp-content/uploads/backwpup-79f882-temp/TUSCANY-BALLOONING-Hot-air-Ballooning-in-Tuscany.pluginlist.2020-12-01.txt.gz): failed to open stream: operation failed
[01-Dec-2020 18:50:28] ERROR: Can not open target file for writing.
[01-Dec-2020 18:50:28] 2. Trying to generate a file with installed plugin names …
[01-Dec-2020 18:50:28] WARNING: fopen(compress.zlib:///web/htdocs/www.tuscanyballooning.com/home/wordpress/wp-content/uploads/backwpup-79f882-temp/TUSCANY-BALLOONING-Hot-air-Ballooning-in-Tuscany.pluginlist.2020-12-01.txt.gz): failed to open stream: operation failed
[01-Dec-2020 18:50:28] ERROR: Can not open target file for writing.
[01-Dec-2020 18:50:28] 3. Trying to generate a file with installed plugin names …
[01-Dec-2020 18:50:28] WARNING: fopen(compress.zlib:///web/htdocs/www.tuscanyballooning.com/home/wordpress/wp-content/uploads/backwpup-79f882-temp/TUSCANY-BALLOONING-Hot-air-Ballooning-in-Tuscany.pluginlist.2020-12-01.txt.gz): failed to open stream: operation failed
[01-Dec-2020 18:50:28] ERROR: Can not open target file for writing.
[01-Dec-2020 18:50:28] ERROR: Step aborted: too many attempts!
[01-Dec-2020 18:50:28] 1. Trying to generate a manifest file …
[01-Dec-2020 18:50:28] Added manifest.json file with 7.02 KB to backup file list.
[01-Dec-2020 18:50:29] 1. Trying to create backup archive …
[01-Dec-2020 18:50:29] Compressing files as TarGz. Please be patient, this may take a moment.
[01-Dec-2020 18:58:06] Backup archive created.
[01-Dec-2020 18:58:06] Archive size is 399.38 MB.
[01-Dec-2020 18:58:06] 44636 Files with 746.29 MB in Archive.
[01-Dec-2020 18:58:09] 1. Try to send backup file to Dropbox …
[01-Dec-2020 18:58:09] Authenticated with Dropbox of user: Tuscany Ballooning
[01-Dec-2020 18:58:09] Uploading to Dropbox …
[01-Dec-2020 18:58:09] Beginning new file upload session
[01-Dec-2020 19:13:00] ERROR: Aborted by user!
[01-Dec-2020 19:13:00] ERROR: Job has ended with errors in 1422 seconds. You must resolve the errors for correct execution.

Hi, Thanks again for your reply!
PHP version is 7.1.11
here is the debug info:

WordPress version: 5.5.3
BackWPup version: 3.8.0
PHP version: 7.1.33 (64bit)
MySQL version: 5.5.62-38.14-log
cURL version: 7.58.0
cURL SSL version: OpenSSL/1.0.2n
WP-Cron url: https://www.tuscanyballooning.com/wordpress/wp-cron.php
Server self connect: Response Test O.K.
Document root: /web/htdocs/www.tuscanyballooning.com/home/
Temp folder: /web/htdocs/www.tuscanyballooning.com/home/wordpress/wp-content/uploads/backwpup-79f882-temp/
Log folder: /web/htdocs/www.tuscanyballooning.com/home/wordpress/wp-content/uploads/backwpup-79f882-logs/
Server: Apache
Operating System: Linux
PHP SAPI: cgi-fcgi
Current PHP user:
Maximum execution time: 300 seconds
BackWPup maximum script execution time: 30 seconds
Alternative WP Cron: Off
Disabled WP Cron: On
CHMOD Dir: 493
Server Time: 10:36
Blog Time: 11:36
Blog Timezone: Europe/Rome
Blog Time offset: 1 hours
Blog language: en-US
MySQL Client encoding: utf8
PHP Memory limit: 256M
WP memory limit: 40M
WP maximum memory limit: 256M
Memory in use: 102.00 MB
Disabled PHP Functions:: system, popen, dl, passthru, proc_open, shell_exec
Loaded PHP Extensions:: Core, PDO, Phar, Reflection, SPL, SimpleXML, SourceGuardian, bcmath, bz2, calendar, cgi-fcgi, ctype, curl, date, dom, exif, fileinfo, filter, ftp, gd, gettext, hash, iconv, imagick, imap, ionCube Loader, json, libxml, mbstring, mcrypt, mysqli, mysqlnd, openssl, pcre, pdo_mysql, pdo_sqlite, posix, session, soap, sqlite3, standard, tidy, tokenizer, wddx, xml, xmlreader, xmlwriter, xsl, zlib