By design RadFileExplorer should show arrows/plus signs only before the folders which are not empty. This is not valid, though, when we are speaking about root folders. When you have more than one root folder, only the first one's content will be listed on load - the other root folders content will be checked on demand and until then a plus sign will be shown. If these are the arrows you do not want to appear - I am afraid that currently this behavior cannot be controlled.
If you have arrows before each nested folder, though - this behavior is unexpected and will need to investigate the exact configuration what is causing the issue. It will be really helpful if you send us a sample fully runnable project demonstrating the case
so we could examine it on our side.
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