TYPO3 Core

using a TS like

lib.mainMenu = HMENU
lib.mainMenu.1.target = _top
lib.mainMenu.maxItems = 6
lib.mainMenu.special = directory
lib.mainMenu.special.value = 35
lib.mainMenu.entryLevel = 0
lib.mainMenu.1 = IMGMENU
lib.mainMenu.1.imgMapExtras = <AREA SHAPE="rect" alt="Startseite" COORDS="5,5,69,70" href="http://www.althoff-fam.de" target="_top">
lib.mainMenu.1 {
    main.XY = 800, 100
    main.10 = IMAGE
    main.10.file = fileadmin/news_import/0ad9a23cb4aec59086d4d4e838c0e8cb51a4dc226eaadea82b2604fa50752d17_3f5df0389758767989845a628fc65184.jpg

    dWorkArea = 200, 94  
    NO.distrib = textX+10,0
    NO.10 = TEXT
    NO.10 {
        text.field = title
        fontSize = 12
        fontWeight = bold
        fontColor = #023294
        offset = 0,0
        imgMap.explode = 3,2
      }
      NO.20 = || BOX
      NO.20 {
        dimensions = -5, -9, 1, 11
        color = white  
    }
}

page.19 < lib.mainMenu

creates exception

Argument 1 passed to TYPO3\CMS\Frontend\Resource\FilePathSanitizer::sanitize() must be of the type string, null given, called in /app/web/typo3/sysext/frontend/Classes/Imaging/GifBuilder.php on line 686