I see it’s impossible to use MT 4.2 at the moment.
I will do some test on a test website to understand all the news and strange behaviour this implementation has. On the production website it’s unusable. Too many errors. If there’s something that make a webmaster angry is a software that doesn’t do what expected to do, and that previous installations do perfectly.
Luciano
Reported on Movable Type 4.2

HTTP 501 errors should not be happening when your browser is the one sending the HTTP data to the server. Chances are, it's some configuration problem with Apache that is only now an issue because of the way that 4.2 works.
That's right, Mike. In fact, with MT 3.2, I saved the Modules without this error.
Now i'm searching for a solution to this problem. It's a "webserver-side" problem, though.
With my shared 1and1 account, i was forced to change most of the files from .cgi to .pl Now, everything is set up, but from the dashboard all links i click on are still calling the original .cgi files, not the .pl files that are present. Is there a way for me to make it so that all the admin links will call files with extension .pl not .cgi??
Ps: sorry i can't start a new topic
With my shared 1and1 account, i was forced to change most of the files from .cgi to .pl Now, everything is set up, but from the dashboard all links i click on are still calling the original .cgi files, not the .pl files that are present. Is there a way for me to make it so that all the admin links will call files with extension .pl not .cgi??
Ps: sorry i can't start a new topic
Look through this list of configuration directives. It has a load of script directives that let you redefine the names of MT scripts. For example, you can use "AdminScript mt.pl" to tell Movable Type to use mt.pl instead of mt.cgi. Look around for those (CommentScript and TrackbackScript are two you definitely should look at as well).