when plugin manager downloads the plugin it creates a hash value of this dll and tries
to compare it with the one confgirued by the author. If this fails, because plugin manager
wasn’t able to load the hash or hash value is incorrect etc. you will get this message.
Normally, you can ignore it but of course there is a chance, that the sourceforge website
was hacked and the dll which you want to load has been compromised.
So, it’s up to you do decide if you want to use the dll or not.

Cheers
Claudia