Shahjada

paypal standard integrated with premium package and it doesn’t require API certificate or signature, which method from paypal are you using there?

No such option, but it is a good idea and I’ve noted it to implement in next update of the add-on.

Now you have latest version but it looks like still not working for you, the reason could be something related with your server, I need to check it in your installation, please make download-manager files writable, as ftp is not working for me ( https://www.evernote.com/shard/s349/sh/fa62ecde-df16-4d76-a1bc-089aec255492/b9bd0fafe24e94494191d4d68f684687/deep/0/FileZilla.png ). Guessing, it could be related to mycrypt or cache dir permission.

@piggybank, in latest version we have added a button with that text field to reset base dir if it is messed up somehow.

Should be ok now.

I’ve updated in server, please download the plugin again and update.

it is because duplicate page slug, replace “downloads” with something else like “file-download”

it is because your server php version need to be at least 5.4 for this add-on ( only for advanced search feature ), but if you don’t need that feature you can disable the code using return 0; after function name or give me temporary wp-admin login info, I can do that for you.

ok now, it was because duplicate “downloads” slug.

please give me ftp access to plugins dir, I tried to delete the plugin from wp-admin to install updated one, it is not allowing me to delete or upload

ok now http://welch.easyitsupport.com/download/catch-basin-type-a-flat-top-with-48-opening-10-dia/

You need to create a custom link template, docs for templates are here http://www.wpdownloadmanager.com/doc/templates/ , FYI: while creating link template you simply need to skip [page_link] tag to avoid link to details page.
Yes, you can use your own custom html/css with link template.