“they display the wpdmpro logo even though it’s a paid version?!” not clear. anyhow, send a temporary wp-admin login info to support@wpdownloadmanager.com with this post post link
actually it renames file if already exists in server, anyhow we are adding new option with next update, where you will be able to choose rename or overwrite.
few more days. but if you need the feature urgently, please send a temporary wp-admin login info to support@wpdownloadmanager.com with this forum post link
as it appeared suddenly now after it was working fine for a period , it could be an issue with your server, may you output buffering disabled in your server or something else with memory. Please ask server support.
for search option you will need wpdm archive page add-on, thought each category short-code will show a search box which will searhc only within that category,
