Backup terminates with “Trying to make a list of folders to back up”

I’ve seen this mentioned in another thread with no resolution. I’m running into an issue where including the ‘uploads’ folder is the difference between success and failure for a full backup (SQL, files, plugins list).

Without the uploads folder included in the backup, it works fine. With the uploads folder included, even with all subfolders excluded, or even if the uploads folder is effectively empty, the backup fails without a warning or error. It just terminates after the message “Trying to make a list of folder to back up” and shows a runtime of 0 seconds.

LOG (Failed process, including uploads)
[INFO] BackWPup 3.6.9; A project of Inpsyde GmbH
[INFO] WordPress 5.1.1 on https://www.mindmatters.net/
[INFO] Log Level: Normal
[INFO] BackWPup job: Full Backup
[INFO] Logfile is: backwpup_log_bcdfbb_2019-05-11_08-38-40.html
[INFO] Backup file is: 2019-05-11_08-38-40_Y6H4BQZC01.zip
[11-May-2019 08:38:40] 1. Try to backup database …
[11-May-2019 08:38:40] Connected to database wordpressdb on mmt-[…].rds.amazonaws.com
[11-May-2019 08:39:09] Added database dump “wordpressdb.sql” with 285.58 MB to backup file list
[11-May-2019 08:39:09] Database backup done!
[11-May-2019 08:39:09] 1. Trying to make a list of folders to back up …

LOG (Successful process, excluding uploads)
[INFO] BackWPup 3.6.9; A project of Inpsyde GmbH
[INFO] WordPress 5.1.1 on https://www.mindmatters.net/
[INFO] Log Level: Normal
[INFO] BackWPup job: Full Backup
[INFO] Logfile is: backwpup_log_47b178_2019-05-11_08-32-32.html
[INFO] Backup file is: 2019-05-11_08-32-32_QWH4BQ6501.zip
[11-May-2019 08:32:32] 1. Try to backup database …
[11-May-2019 08:32:32] Connected to database wordpressdb on mmt-mysql3.clvg9vx3y9ni.us-east-1.rds.amazonaws.com
[11-May-2019 08:33:02] Added database dump “wordpressdb.sql” with 285.58 MB to backup file list
[11-May-2019 08:33:02] Database backup done!
[11-May-2019 08:33:02] 1. Trying to make a list of folders to back up …
[11-May-2019 08:33:02] Added “wp-config.php” to backup file list
[11-May-2019 08:33:02] 993 folders to backup.
[11-May-2019 08:33:02] 1. Trying to generate a file with installed plugin names …
[11-May-2019 08:33:02] Added plugin list file “MindMatters-Solutions-LLC.pluginlist.2019-05-11.txt” with 3.90 KB to backup file list.
[11-May-2019 08:33:02] 1. Trying to generate a manifest file …
[11-May-2019 08:33:03] Added manifest.json file with 3.49 KB to backup file list.
[11-May-2019 08:33:03] 1. Trying to create backup archive …
[11-May-2019 08:33:03] Compressing files as ZipArchive. Please be patient, this may take a moment.
[11-May-2019 08:37:42] Backup archive created.
[11-May-2019 08:37:42] Archive size is 66.15 MB.
[11-May-2019 08:37:42] 6134 Files with 390.55 MB in Archive.
[11-May-2019 08:37:42] Job done in 310 seconds.

DEBUG INFO
WordPress version: 5.1.1
BackWPup version: 3.6.9
PHP version: 5.6.40 (64bit)
MySQL version: 5.6.40-log
cURL version: 7.61.1
cURL SSL version: OpenSSL/1.0.2k
WP-Cron url: https://www.mindmatters.net/wp-cron.php
Server self connect: Response Test O.K.
Document root: /var/www/html
Temp folder: /var/www/html/wp-content/backwpup/temp/backwpup-8fc0c3/
Log folder: /var/www/html/wp-content/uploads/backwpup-8fc0c3-logs/
Server: Apache/2.4.39 (Amazon) OpenSSL/1.0.2k-fips PHP/5.6.40
Operating System: Linux
PHP SAPI: apache2handler
Current PHP user: apache
Maximum execution time: 30 seconds
BackWPup maximum script execution time: 0 seconds
Alternative WP Cron: Off
Disabled WP Cron: Off
CHMOD Dir: 493
Server Time: 13:42
Blog Time: 08:42
Blog Timezone:
Blog Time offset: -5 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: 77.75 MB
Loaded PHP Extensions:: Core, PDO, Phar, Reflection, SPL, SimpleXML, apache2handler, bcmath, bz2, calendar, ctype, curl, date, dom, ereg, exif, fileinfo, filter, ftp, gd, gettext, hash, iconv, json, libxml, mbstring, mcrypt, mhash, mysql, mysqli, mysqlnd, openssl, pcre, pdo_mysql, pdo_sqlite, posix, session, shmop, sockets, sqlite3, standard, sysvmsg, sysvsem, sysvshm, tidy, tokenizer, wddx, xml, xmlreader, xmlwriter, xsl, zip, zlib