To change the subgrid icon, refer to this grid option.

$opt["subGridOptions"]["plusicon"] = "ui-icon-carat-1-e";
$opt["subGridOptions"]["minusicon"] = "ui-icon-carat-1-s";

You can see all icon css classes here: https://github.com/mkkeck/jquery-ui-iconfont
append “ui-icon-” before icon name in above sheet.

Most likely this font is updated and we’re using older version. I’ll update + test new version and update you back.

I tried for your case but all related JS libraries needs to be updated for that and it’ll take more testing time.

As an alternate, we also support fontawesome free icons. So you can use:

$opt["subGridOptions"]["plusicon"] = "fa fa-paperclip";