This results in a red error box saying "Error: Call to undefined function mime_content_type()", that the imagebox plugin might be the cause and that more details have been written to the error log.
2023-08-14 08:37:17 F:\www\dowi\lib\plugins\imagebox\syntax.php(50) Error: Call to undefined function mime_content_type()
#0 F:\www\dowi\inc\parser\handler.php(284): syntax_plugin_imagebox->handle(Array, 1, 1047, Object(Doku_Handler))
#1 F:\www\dowi\inc\Parsing\Lexer\Lexer.php(270): Doku_Handler->plugin('[{{ a11:organig...', 1, 1047, 'imagebox')
#2 F:\www\dowi\inc\Parsing\Lexer\Lexer.php(204): dokuwiki\Parsing\Lexer\Lexer->invokeHandler('[{{ a11:organig...', 1, 1047)
#3 F:\www\dowi\inc\Parsing\Lexer\Lexer.php(147): dokuwiki\Parsing\Lexer\Lexer->dispatchTokens('', '[{{ a11:organig...', 'plugin_imagebox', 1047, 1047)
#4 F:\www\dowi\inc\Parsing\Parser.php(109): dokuwiki\Parsing\Lexer\Lexer->parse('Abteilung 11: A...')
#5 F:\www\dowi\inc\parserutils.php(234): dokuwiki\Parsing\Parser->parse('\n====== Abteilu...')
#6 F:\www\dowi\inc\parserutils.php(198): p_get_instructions('====== Abteilun...')
#7 F:\www\dowi\inc\parserutils.php(525): p_cached_instructions('F:/www/dowi/dat...', false, 'a11:start')
#8 F:\www\dowi\inc\parserutils.php(299): p_render_metadata('a11:start', Array)
#9 F:\www\dowi\inc\common.php(266): p_get_metadata('a11:start')
#10 F:\www\dowi\doku.php(97): pageinfo()
#11 {main}
I am running Dokuwiki release 2023-04-04a "Jack Jackrum".