I am on Ubuntu 14.04 and it always show me the little icon for updates, I do it and every time it show me this message :   W:Failed to fetch (http)://ppa.launchpad.net/c-korn/ppa/ubuntu/dists/trusty/main/source/Sources 404 Not Found , W:Failed to fetch (http)://ppa.launchpad.net/c-korn/ppa/ubuntu/dists/trusty/main/binary-amd64/Packages 404 Not Found , W:Failed to fetch (http)://ppa.launchpad.net/c-korn/ppa/ubuntu/dists/trusty/main/binary-i386/Packages 404 Not Found ,       E:Some index files failed to download. They have been ignored, or old ones used instead.   I googled and didn't find any "accurate" solution for this error, do you think is my nvidia driver the problemes ( I use the nvidia driver giving in software and updates : proprietary, tested) ? Because I have some little problems to make my Nvidia drivers work well.
PPA seems to be constantly offline. Whenever I use sudo apt-get update, this error is shown:  W: Failed to fetch http://ppa.launchpad.net/ 404  Not Found   How do I fix these errors?
The kernel and range of the powers of a self-adjoint operator Objects with transparent texture not always show transparency in 3dview For some reason objects don't show their transparency all the time.  In this image the circles in red are suposed to be transparent like the ones in green.    When I select the object in the back, all objects in front of it become opaque.    When I select the two objects that are opaque, then they become transparent as they sould be.    The display is in GLSL mode  These are the material and texture properties      I'm not worried about the final render, just the editing view. I would like to see the actual transparency at editing time only, because the scene is to be imported in a third party game engine.  Blender is v2.68   is the blend file Group by alias (Oracle) How to 'group by' a query using an alias, for example:  select count(*), (select * from....) as alias_column  from table  group by alias_column   I get 'alias_column' : INVALID_IDENTIFIER error message. Why? How to group this query? I'm trying to wrap my head around how SQL Server decides to grant certain rights based on a users login privileges.  If a user is part of a group "READ ONLY" which has access to DB1, but they are also a part of a group "SysAdmin" which has full db owner rights to the same DB1, which rights are they given when they log in?  On a similar note. What if they are part of a group but also have a standalone account with other middle of the road privileges? I've recently noticed an issue with Ubuntu Software Center which I have tried to resolve following the answers provided in  without result and  which partially worked but didn't persist. The Issue After installing 20.04 I opened Ubuntu Software Center and installed a number of apps without any problem - one of which was Stacer which I will use as an example.  In Show Applications the app is clearly present and right clicking on the icon selecting Show Details provides the image above and it works perfectly well. However, if I open Ubuntu Software Center and type in the search bar stacer it reports that no application is found:  Nor is it listed when selecting the Installed tab. This is the setup for for Software and Updates.  There are other applications I have previously installed which are also now reported as No Application found such as gLabels, gscan2pdf and others. Has something changed since I initially installed 20.04.1 and more importantly, how can I restore good order to the Ubuntu Software Center? Is it possible to recover an email that has been clicked "delete forever" in the trash folder? When and where can I find the Tower's exotic item vendor (Xur Agent of the Nine)? What's the simplest way to decrement a date in Javascript by 1 day? I need to decrement a Javascript date by 1 day, so that it rolls back across months/years correctly.  That is, if I have a date of 'Today', I want to get the date for 'Yesterday'.  It always seems to take more code than necessary when I do this, so I'm wondering if there's any simpler way.    What's the simplest way of doing this?  [Edit: Just to avoid confusion in an answer below, this is a JavaScript question, not a Java one.] Home button broken and Notification Center stuck my home button on my ipod touch 5th Gen has been broken for  while so I have been using assistive touch. Earlier on my notification centre got stuck half way down the lock screen, making my ipod completely unusable.   I tried turning it off but the notification centre is blocking the slider and obviously I can't restart it since my home button is broken. Has anyone got any solutions? It's an absolute nightmare! How Do I Allow A Standard User to Install Programs? Yes, I realize that defeats the purpose of standard user. But here is the situation. A friend of mine wants to set up time limits for his home schooled son, and his son needs to be a standard user in order to use Family Safety. But at the same time, his son (who I personally think is way too old to have time limits), needs to be able to update and install some of his games on his computer. So I guess it's just sort of "light" parental control (just something to help him focus and not get distracted with hours of gaming).  It is the basic version of Windows 8.1, so there is no Group Policy editor (gpedit.msc). However, I'm fairly good with computers and I figured out how to install it. But it doesn't have a lot of the features that the "real" gpedit seems to have. Here is an example of what is in my gpedit: How to Search for Files Recursively into Subdirectories I am trying to look for all XML files in a particular directory and all sub-directories (recursively) inside it.  ls -R *.xml is only listing files in the current directory. I am quite sure, the sub-folders themselves have several .xml files, but none are showing up.  Is this a configuration issue? How would I prove that any binary tree that has n leaves has precisely $2n-1$ nodes ?  Given that a binary tree is either a single node "o" or a node with the left and right subtrees contains a binary tree        o  /       \ binary  binary tree    tree   Any help would be appreciated ! I am trying to write an if statement to test whether there are any files matching a certain pattern. If there is a text file in a directory it should run a given script.  My code currently:  if [ -f /*.txt ]; then ./script fi   Please give some ideas; I only want to run the script if there is a .txt in the directory. Find $f$ if $$ f(x)+f\left(\frac{1}{1-x}\right)=x $$ I think, that I have to find x that $f(x) = f\left(\frac{1}{1-x}\right)$ I've tried to put x which make $x = \frac{1}{1 - x}$, but this equation has no roots in real numbers. A real nxn matrix always has a real eigenvalue when n is odd what do it mean by "A real nxn matrix always has a real eigenvalue when n is odd?" Shouldnt it be that regardless of odd or even there will always have a real root?  hope to hear from you guys soon:) Split a string by a delimiter in python Why can some holodeck matter leave the holodeck, while other holodeck matter (notably people) cannot? How to get video duration, dimension and size in PHP? How to format a USB or external drive? Using Ubuntu 11.10, how do I format an external or USB drive? I don't find an option to 'format' when I right click. In the new version, the drives don't come up on the desktop, but instead come on the Launcher. How to add startup applications in lubuntu?