download-link is not sent

hello!

i am using the paypal-sandbox to test everything. i get the mails for the business which says it is paid. buyer gets email with successful payment and gets redirected to the thank you page. no email with the download link is sent.

download is correctly set – file is chosen from wordpress media

the debug text file stays empty

in the orders section i have some error messages:

Column Customer:
Warning: Illegal string offset ‘first_name’ in /home/.sites/307/site4068059/web/wp-content/plugins/sell-digital-downloads/start.php on line 1376 Warning: Illegal string offset ‘last_name’ in /home/.sites/307/site4068059/web/wp-content/plugins/sell-digital-downloads/start.php on line 1376

Column Amount Paid:
Warning: Illegal string offset ‘amount_paid’ in /home/.sites/307/site4068059/web/wp-content/plugins/sell-digital-downloads/start.php on line 1384
EUR

Column Payment Status:
Warning: Illegal string offset ‘status’ in /home/.sites/307/site4068059/web/wp-content/plugins/sell-digital-downloads/start.php on line 1392 Warning: Illegal string offset ‘status’ in /home/.sites/307/site4068059/web/wp-content/plugins/sell-digital-downloads/start.php on line 1392

when i open the order it is completely empty

i would be glad for any help or idea!

thank you,
stefan.

below is my wordpress-status-report

### wp-core ###

version: 5.4.1
site_language: de_DE
user_language: de_DE
timezone: Europe/Vienna
permalink: /%postname%/
https_status: true
user_registration: 0
default_comment_status: closed
multisite: false
user_count: 135
dotorg_communication: true

### wp-paths-sizes ###

wordpress_path: /home/.sites/307/site4068059/web
wordpress_size: 636,60 MB (667524319 bytes)
uploads_path: /home/.sites/307/site4068059/web/wp-content/uploads
uploads_size: 1,04 GB (1119890285 bytes)
themes_path: /home/.sites/307/site4068059/web/wp-content/themes
themes_size: 83,92 MB (87994390 bytes)
plugins_path: /home/.sites/307/site4068059/web/wp-content/plugins
plugins_size: 36,80 MB (38589433 bytes)
database_size: 28,11 MB (29479290 bytes)
total_size: 1,81 GB (1943477717 bytes)

### wp-active-theme ###

name: Enfold Child (enfold-child)
version: 1.0
author: Kriesi
author_website: https://www.kriesi.at
parent_theme: Enfold (enfold)
theme_features: avia_exclude_bbPress, deactivate_tribe_events_calendar, avia_exclude_GFForms, avia_exclude_menu_exchange, avia_exclude_relevanssi, avia_exclude_WooCommerce, avia_exclude_wpSEO, avia_exclude_wpml, avia_exclude_instagram_feed, avia_mega_menu, avia_improved_backend_style, avia_option_pages_toggles, avia_sidebar_manager, automatic-feed-links, nav_menus, menus, widgets, post-formats, avia-disable-default-shortcodes, avia_post_meta_compat, force-post-thumbnails-in-widget, post-thumbnails, title-tag, editor-styles, editor-style, customize-selective-refresh-widgets, responsive-embeds, editor-color-palette, editor-font-sizes
theme_path: /home/.sites/307/site4068059/web/wp-content/themes/enfold-child

### wp-parent-theme ###

name: Enfold (enfold)
version: 4.7.4
author: Kriesi
author_website: https://kriesi.at
theme_path: /home/.sites/307/site4068059/web/wp-content/themes/enfold

### wp-themes-inactive (3) ###

Twenty Nineteen: version: 1.5, author: WordPress-Team
Twenty Seventeen: version: 2.3, author: WordPress-Team
Twenty Twenty: version: 1.2, author: WordPress-Team

### wp-plugins-active (13) ###

Autoptimize: version: 2.7.1, author: Frank Goossens (futtta)
Disable Gutenberg: version: 2.1, author: Jeff Starr
Easy WP SMTP: version: 1.3.9.3, author: wpecommerce, alexanderfoxc
Envato Market: version: 2.0.1, author: Envato
Events Manager: version: 5.9.7.3, author: Marcus Sykes
Events Manager Pro: version: 2.6.7.2, author: NetWebLogic
Imsanity: version: 2.6.0, author: Exactly WWW
Invisible reCaptcha: version: 1.2.3, author: Mihai Chelaru
Rank Math SEO: version: 1.0.42.3, author: Rank Math
Tuxedo Big File Uploads: version: 1.2, author: Trevor Anderson
UpdraftPlus - Backup/Restore: version: 2.16.23.24, author: UpdraftPlus.Com, DavidAnderson
WordPress iSell - Sell Digital Downloads: version: 2.2.7, author: wpecommerce, wp.insider
WP User Avatar: version: 2.2.6, author: ProfilePress

### wp-plugins-inactive (1) ###

Disable REST API: version: 1.5, author: Dave McHale

### wp-media ###

image_editor: WP_Image_Editor_GD
imagick_module_version: Nicht verfügbar
imagemagick_version: Nicht verfügbar
gd_version: bundled (2.1.0 compatible)
ghostscript_version: 8.70

### wp-server ###

server_architecture: Linux 3.10.0-962.3.2.lve1.5.27.el6h.x86_64 x86_64
httpd_software: Apache
php_version: 7.2.30 64bit
php_sapi: fpm-fcgi
max_input_variables: 1000
time_limit: 113
memory_limit: 320M
max_input_time: 60
upload_max_size: 200M
php_post_max_size: 200M
curl_version: 7.61.0 OpenSSL/1.0.1e
suhosin: false
imagick_availability: false
htaccess_extra_rules: true

### wp-database ###

extension: mysqli
server_version: 5.5.62
client_version: mysqlnd 5.0.12-dev - 20150407 - $Id: 3591daad22de08524295e1bd073aceeff11e6579 $

### wp-constants ###

WP_HOME: undefined
WP_SITEURL: undefined
WP_CONTENT_DIR: /home/.sites/307/site4068059/web/wp-content
WP_PLUGIN_DIR: /home/.sites/307/site4068059/web/wp-content/plugins
WP_MAX_MEMORY_LIMIT: 512M
WP_DEBUG: false
WP_DEBUG_DISPLAY: true
WP_DEBUG_LOG: false
SCRIPT_DEBUG: false
WP_CACHE: false
CONCATENATE_SCRIPTS: undefined
COMPRESS_SCRIPTS: undefined
COMPRESS_CSS: undefined
WP_LOCAL_DEV: undefined
DB_CHARSET: utf8mb4
DB_COLLATE: undefined

### wp-filesystem ###

wordpress: writable
wp-content: writable
uploads: writable
plugins: writable
themes: writable

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