in reply to
DBI connect is failing with Perl v5.16.3
What you don't mention is that you did a force install of this module, because a prerequisite (Net::Demon) isn't installed. After much talk in the CB to draw these facts (and others) from you, it transpires that you later did a force install of Net::Demon also, based upon a false understanding of the test results. If you're going force install modules and their prerequisites without bothering to find out if the failures are pertinent then you're going to continue to hit problems like this.
I've repeatedly told you in the chatterbox, but once more in case you have problems understanding. When you want to install a module, check the open bugs, there may be some issues/patches you need to address/apply depending on your platform/perl version. If tests fail find out why they fail, perhaps there's something you need to do to make this module work within your environment. It's a waste of your time, and everyone else’s, for you to keep asking the same questions over and over while ignoring the answers. Please read and understand How do I post a question effectively?.