Fatal Error after upgrade to CMSMS v2.2.21

[Arjuna]

Dear yall
After upgrading to CMSMS2.2.21 i get the following fatal error:

Fatal error: Uncaught TypeError: Illegal offset type in /var/www/vhosts/yogae.org/domains/yogae.org/public_html/modules/MenuManager/MenuManager.module.php:114 Stack trace: #0 /var/www/vhosts/yogae.org/domains/yogae.org/public_html/modules/MenuManager/action.default.php(183): MenuManager->GetChildNodes() #1 /var/www/vhosts/yogae.org/domains/yogae.org/public_html/lib/classes/class.CMSModule.php(1407): include('...') #2 /var/www/vhosts/yogae.org/domains/yogae.org/public_html/lib/classes/class.CMSModule.php(1483): CMSModule->DoAction() #3 /var/www/vhosts/yogae.org/domains/yogae.org/public_html/lib/functions/module.functions.php(106): CMSModule->DoActionBase() #4 /var/www/vhosts/yogae.org/domains/yogae.org/public_html/lib/classes/class.CMSModule.php(253): cms_module_plugin() #5 /var/www/vhosts/yogae.org/domains/yogae.org/public_html/tmp/templates_c/70e60997609f3eba38ab7b26b669ccfd1b81b07a_0.tpl_body.4.php(50): CMSModule::function_plugin() #6 /var/www/vhosts/yogae.org/domains/yogae.org/public_html/lib/smarty/sysplugins/smarty_template_resource_base.php(123): content_6769b9e7991394_49139609() #7 /var/www/vhosts/yogae.org/domains/yogae.org/public_html/lib/smarty/sysplugins/smarty_template_compiled.php(114): Smarty_Template_Resource_Base->getRenderedTemplateCode() #8 /var/www/vhosts/yogae.org/domains/yogae.org/public_html/lib/smarty/sysplugins/smarty_internal_template.php(217): Smarty_Template_Compiled->render() #9 /var/www/vhosts/yogae.org/domains/yogae.org/public_html/lib/smarty/sysplugins/smarty_internal_templatebase.php(238): Smarty_Internal_Template->render() #10 /var/www/vhosts/yogae.org/domains/yogae.org/public_html/lib/smarty/sysplugins/smarty_internal_templatebase.php(116): Smarty_Internal_TemplateBase->_execute() #11 /var/www/vhosts/yogae.org/domains/yogae.org/public_html/lib/classes/internal/class.CMS_Smarty_Template.php(20): Smarty_Internal_TemplateBase->fetch() #12 /var/www/vhosts/yogae.org/domains/yogae.org/public_html/index.php(160): CMS_Smarty_Template->fetch() #13 {main} thrown in /var/www/vhosts/yogae.org/domains/yogae.org/public_html/modules/MenuManager/MenuManager.module.php on line 114

How to solve this?
Thanks alot and very much appreciated, Regards Arjuna (from The Netherlands, Utrecht)

My technical info:
----------------------------------------------

Cms Version: 2.2.21

Installed Modules:

AdminSearch: 1.0.6
CMSContentManager: 1.1.13
CmsJobManager: 1.0.0
DesignManager: 1.1.11
FileManager: 1.6.16
FilePicker: 1.0.8
FormBuilder: 1.2
MenuManager: 1.50.3
MicroTiny: 2.2.5
ModuleManager: 2.1.9
Navigator: 1.0.11
News: 2.51.13
Search: 1.53
ThemeManager: 1.1.8
TinyMCE: 2.9.12
UserGuide: 1.0.0

Config Information:

php_memory_limit:
max_upload_size: 128000000
url_rewriting: none
page_extension:
query_var: page
auto_alias_content: true
locale:
set_names: true
timezone: Europe/Amsterdam
permissive_smarty: false

Php Information:

phpversion: 8.1.31
md5_function: On (True)
json_function: On (True)
gd_version: 2
tempnam_function: On (True)
magic_quotes_runtime: Off (False)
E_ALL: 22519
E_STRICT: 0
E_DEPRECATED: 0
test_file_timedifference: No time difference found
test_db_timedifference: No time difference found
create_dir_and_file: 1
memory_limit: 256M
max_execution_time: 120
register_globals: Off (False)
output_buffering: 4096
disable_functions: opcache_get_status
open_basedir: /var/www/vhosts/yogae.org/:/tmp/
test_remote_url: Success
file_uploads: On (True)
post_max_size: 128M
upload_max_filesize: 128M
session_save_path: No check because open basedir active
session_use_cookies: On (True)
xml_function: On (True)
xmlreader_class: On (True)
check_ini_set: Off (False)
curl: On

Performance Information:

allow_browser_cache: On (True)
browser_cache_expiry: 60
php_opcache: On (True)
smarty_cache: On (True)
smarty_compilecheck: On (True)
auto_clear_cache_age: On (True)
Server Information:

Server Software: Apache
Server Api: fpm-fcgi
Server Os: Linux 4.18.0-553.16.1.el8_10.x86_64 On x86_64
Server Db Type: MySQL (mysqli)
Server Db Version: 10.11.10
Server Db Grants: Could not find a suitable "GRANT ALL" permission, this does not necessarily lead to problems... But if you have problems installing/removing modules or adding and deleting items/pages this could be the cause!

Permission Information:

tmp: /var/www/vhosts/yogae.org/domains/yogae.org/public_html/tmp (0755)
tmp_cache: /var/www/vhosts/yogae.org/domains/yogae.org/public_html/tmp/cache (0755)
templates_c: /var/www/vhosts/yogae.org/domains/yogae.org/public_html/tmp/templates_c (0755)
modules: /var/www/vhosts/yogae.org/domains/yogae.org/public_html/modules (0755)
uploads: /var/www/vhosts/yogae.org/domains/yogae.org/public_html/uploads (0755)
File Creation Mask (umask): /var/www/vhosts/yogae.org/domains/yogae.org/public_html/tmp/cache (0755)
config_file: 0444
----------------------------------------------

[DIGI3]

MenuManger is not compatible with PHP 8, it has long since been replaced with Navigator. I'd restore from backup and uninstall it before upgrading (migrating your menus and templates as needed). If you can't go back, then rename the MenuManager folder in your modules folder, then comment out or remove any references to it in your page templates.