Some programs made in a certain programming language require additional files to run properly. This isn't the only program that gives these errors, and the solution is to simply replace the old version of the file with a new one, or, if the file doesn't exist at all, to put it there. It's nothing to worry about.
More people have reported this problem with Plus! Tweak!; I took a look at its thread (
http://shoutbox.menthix.net/showthread.php?tid=25692) before I answered your question, and saw this was exactly the response the author (Choli) gave there
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