Error message -WARNING: call_user_func_array() expects parameter 1 to be a valid

hi. the backup for this site is failing with the following error message:
WARNING: call_user_func_array() expects parameter 1 to be a valid callback, function ‘menu_item_text’ not found or invalid function name

Here is the full log. Can you please help thank you.

[INFO] BackWPup job: DFH to Dropbox
[INFO] Logfile is: backwpup_log_d2bd96_2018-12-18_12-18-20.html
[INFO] Backup file is: backwpup_SDJL3FSZ01_2018-12-18_12-18-20.zip
[18-Dec-2018 12:18:20] 1. Try to backup database …
[18-Dec-2018 12:18:20] Connected to database c15_d4h on burnejones.artonezero.com
[18-Dec-2018 12:18:20] Added database dump “c15_d4h.sql” with 2.25 MB to backup file list
[18-Dec-2018 12:18:20] Database backup done!
[18-Dec-2018 12:18:20] 1. Trying to make a list of folders to back up …
[18-Dec-2018 12:18:24] Added “wp-config.php” to backup file list
[18-Dec-2018 12:18:24] 957 folders to backup.
[18-Dec-2018 12:18:25] 1. Trying to create a WordPress export to XML file …
[18-Dec-2018 12:18:26] Check WP Export file …
[18-Dec-2018 12:18:26] WP Export file is a valid WXR file.
[18-Dec-2018 12:18:26] Added XML export “Design_for_Homes.wordpress.2018-12-18.xml” with 931.63 KB to backup file list.
[18-Dec-2018 12:18:26] 1. Trying to generate a file with installed plugin names …
[18-Dec-2018 12:18:26] Added plugin list file “Design-for-Homes.pluginlist.2018-12-18.txt” with 2.20 KB to backup file list.
[18-Dec-2018 12:18:26] 1. Trying to generate a manifest file …
[18-Dec-2018 12:18:26] Added manifest.json file with 6.36 KB to backup file list.
[18-Dec-2018 12:18:26] 1. Trying to create backup archive …
[18-Dec-2018 12:18:26] Compressing files as ZipArchive. Please be patient, this may take a moment.
[18-Dec-2018 12:18:26] Array ( [0] => /var/www/clients/client15/web477/web/wp-content/uploads/backwpup-d2bd96-temp/c15_d4h.sql [1] => /var/www/clients/client15/web477/web/wp-config.php [2] => /var/www/clients/client15/web477/web/wp-content/uploads/backwpup-d2bd96-temp/Design_for_Homes.wordpress.2018-12-18.xml [3] => /var/www/clients/client15/web477/web/wp-content/uploads/backwpup-d2bd96-temp/Design-for-Homes.pluginlist.2018-12-18.txt [4] => /var/www/clients/client15/web477/web/wp-content/uploads/backwpup-d2bd96-temp/manifest.json [5] => /var/www/clients/client15/web477/web/wp-content/uploads/backwpup-d2bd96-temp/backwpup_readme.txt )
[18-Dec-2018 12:20:30] Backup archive created.
[18-Dec-2018 12:20:30] Archive size is 211.74 MB.
[18-Dec-2018 12:20:30] 6924 Files with 278.40 MB in Archive.
[18-Dec-2018 12:20:30] 1. Try to send backup file to Dropbox …
[18-Dec-2018 12:20:31] Authenticated with Dropbox of user: Fiona Birkbeck
[18-Dec-2018 12:20:31] Uploading to Dropbox …
[18-Dec-2018 12:20:31] Beginning new file upload session
[18-Dec-2018 12:22:00] Finishing upload session with a total of 212 MB uploaded
[18-Dec-2018 12:22:03] Backup transferred to /Design-for-Homes/backwpup_SDJL3FSZ01_2018-12-18_12-18-20.zip
[18-Dec-2018 12:22:04] 1. Trying to check database …
[18-Dec-2018 12:22:04] Database check done!
[18-Dec-2018 12:22:04] WARNING: call_user_func_array() expects parameter 1 to be a valid callback, function ‘menu_item_text’ not found or invalid function name
[18-Dec-2018 12:22:04]
[18-Dec-2018 12:22:04] WARNING: Job finished with warnings in 224 seconds. Please resolve them for correct execution.

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