As postend in my last support request we changed the server. Since then following issue occurs:
When posting a new database record it comes to the error code: EX1366 and the record is not saved, here is the content of the system log to that issue:
INSERT INTO `cms_custom_database_7` ( `record_publish_date`, `record_last_comment`, `member_id`, `record_last_comment_by`, `record_last_comment_name`, `record_last_review`, `category_id`, `record_approved`, `record_locked`, `record_views`, `record_pinned`, `record_featured`, `record_future_date`, `record_comments`, `record_reviews`, `record_comments_queued`, `record_comments_hidden`, `record_image`, `record_image_thumb`, `field_45`, `field_46`, `field_72`, `field_47`, `field_48`, `field_49`, `field_60`, `field_61`, `field_63`, `field_62`, `field_65`, `field_81`, `field_66`, `field_67`, `field_68`, `field_69`, `field_70`, `field_71`, `field_112`, `field_64`, `field_74`, `record_saved`, `record_updated`, `record_allow_comments`, `record_dynamic_furl`, `record_static_furl` ) VALUES ( 1645625790, 1645625790, 9, 9, 'testuser10', 1645625790, 82, 1, false, 0, 0, 0, 0, 0, 0, 0, 0, NULL, NULL, 'Test Titel', '<p>
test test test test test
</p>', '', 'https://www.testseite.de/', '', '', 'aussehen_0', 'service_0', 'pl_0', 'social_0', 'konv_0', 'serviceangeboten_ohne_angabe', 'fotos_ohne_angabe', 'ontime_ohne_angabe', 'outfit_ohne_angabe', 'alter_ohne_angabe', 'beratung_ohne_angabe', 'time_ohne_angabe', 'key_ja', '', '', 1645625790, 1645625790, true, 'test-titel', NULL )
IPS\Db\Exception: Incorrect decimal value: '' for column `db15*******`.`cms_custom_database_7`.`field_64` at row 1 (1366)
#0 /home/www/doc/*****/mydomain.de/www/system/Db/Db.php(948): IPS\_Db->preparedQuery('/*db*****0022::...', Array)
#1 /home/www/doc/*****/mydomain.de/www/system/Patterns/ActiveRecord.php(487): IPS\_Db->insert('cms_custom_data...', Array)
#2 /home/www/doc/*****/mydomain.de/www/applications/cms/sources/Records/Records.php(1904): IPS\Patterns\_ActiveRecord->save()
#3 /home/www/doc/*****/mydomain.de/www/applications/cms/sources/Records/Records.php(1073): IPS\cms\_Records->save()
#4 /home/www/doc/*****/mydomain.de/www/system/Content/Item.php(397): IPS\cms\_Records->processForm(Array)
#5 /home/www/doc/*****/mydomain.de/www/applications/cms/sources/Records/Records.php(2354): IPS\Content\_Item::createFromForm(Array, Object(IPS\cms\Categories7), true)
#6 /home/www/doc/*****/mydomain.de/www/system/Content/Item.php(133): IPS\cms\_Records::createFromForm(Array, Object(IPS\cms\Categories7))
#7 /home/www/doc/*****/mydomain.de/www/applications/cms/modules/front/database/category.php(733): IPS\Content\_Item::create(Object(IPS\cms\Categories7))
#8 /home/www/doc/*****/mydomain.de/www/system/Dispatcher/Controller.php(90): IPS\cms\modules\front\database\_category->form()
#9 /home/www/doc/*****/mydomain.de/www/applications/cms/sources/Databases/Dispatcher.php(327): IPS\Dispatcher\_Controller->execute()
#10 /home/www/doc/*****/mydomain.de/www/applications/cms/widgets/Database.php(128): IPS\cms\Databases\_Dispatcher->run()
#11 /home/www/doc/*****/mydomain.de/www/applications/cms/sources/Pages/Page.php(1300): IPS\cms\widgets\_Database->render()
#12 /home/www/doc/*****/mydomain.de/www/applications/cms/sources/Pages/Page.php(2259): IPS\cms\Pages\_Page->getWidgets()
#13 /home/www/doc/*****/mydomain.de/www/applications/cms/modules/front/pages/page.php(227): IPS\cms\Pages\_Page->output()
#14 /home/www/doc/*****/mydomain.de/www/system/Dispatcher/Controller.php(90): IPS\cms\modules\front\pages\_page->__call('form', Array)
#15 /home/www/doc/*****/mydomain.de/www/applications/cms/modules/front/pages/page.php(33): IPS\Dispatcher\_Controller->execute()
#16 /home/www/doc/*****/mydomain.de/www/system/Dispatcher/Dispatcher.php(152): IPS\cms\modules\front\pages\_page->execute()
#17 /home/www/doc/*****/mydomain.de/www/index.php(13): IPS\_Dispatcher->run()
#18 {main}
BACKTRACE
#0 /home/www/doc/15***/mydomain.de/www/init.php(995): IPS\_Log::log('INSERT INTO `cm...', 'uncaught_except...')
#1 [internal function]: IPS\IPS::exceptionHandler(Object(IPS\Db\Exception))
#2 {main}
This occurs to all usergroups except the admin account, there it works fine as expected. Note, I haven't chanted anything regarding usergroups or permissions. Thanks for your help.