ShowAllAchors 1.0 needs update for TS 5.2.

I have used your trick from Responsive Image to fix the plugin but can't send you a PR.

  public static function PageRunScript($cmd) {
    global $page, $dirPrefix;
    if( \gp\tool::LoggedIn() ){
      $ckeditor_basepath = (version_compare(gpversion, '5.1') > 0) ?
       \gp\tool::GetDir('/include/thirdparty/ckeditor/') :
       \gp\tool::GetDir('/include/thirdparty/ckeditor_34/');

...

          background: url(' . $dirPrefix . $ckeditor_basepath . 'plugins/link/images/anchor.png) no-repeat left center;

UPD

FYI. I have also changed style of marker to have less influence on the layout of the page.

 <style>
        body.showAllAnchors .GPAREA a[id]::before,
        body.showAllAnchors .GPAREA a[name]::before {
          content: "";
          background: url(' . $dirPrefix . $ckeditor_basepath . 'plugins/link/images/anchor.png) no-repeat left top, #0000ff33;
          border: 1px dotted #0000ff;
          z-index: 10;
          width: 100%;
          height: 100%;
          position: absolute;
          top: 0;
          left: 0;
          opacity: 0.6;
        } 

Thanks. I added the compatibility fix and put it on GitHub

position: absolute;
top: 0;
left: 0;

This will only work inside a non-position-static context