Tag error: <txp:com_connect_submit /> ->  8192: strlen(): Passing null to parameter #1 ($string) of type string is deprecated while parsing form default on page static_flex

com_connect_submit()
textpattern/vendors/Textpattern/Tag/Registry.php:140 call_user_func()
textpattern/lib/txplib_publish.php:559 Textpattern\Tag\Registry->process()
textpattern/lib/txplib_publish.php:409 processTags()
textpattern/plugins/com_connect/com_connect.php:178 parse()
com_connect()
textpattern/vendors/Textpattern/Tag/Registry.php:140 call_user_func()
textpattern/lib/txplib_publish.php:559 Textpattern\Tag\Registry->process()
textpattern/lib/txplib_publish.php:409 processTags()
textpattern/publish/taghandlers.php:2908 parse()