Just now, after waking my fully up-to-date install of 16.04 (updated this afternoon) from suspend, I found that a lot of text is randomly missing from certain applications. This has happened twice before a while ago. For example:        Logging out and back in fixed it, but I'd like to know what caused this...  System info:   Dell E6530 Nvidia Prime with Nvidia disabled and only using the Intel card
I have a fresh installation of Ubuntu 14.10 on my laptop. It appears that letters are missing from files and folders, as well as menus and configuration windows. I'm not sure where to start in order to fix this.
Page layout assignments with XML metadata API How do I define page layout assignments for different record types via metadata XML files? How to make a different font and color of text in labels? Is it possible to make a bold or italic, and change the color of individual words Label?  Example: the first line is bold in red text, font 12, second row 10 green italic font I am looking for a way to clean up the mess when my top-level script exits.  Especially if I want to use set -e, I wish the background process would die when the script exits. For a given inner product space $V$, I would like to prove the inequality $$\|\mathbf{x}+\mathbf{y}\|^2 + \|\mathbf{x}-\mathbf{y}\|^2 = 2(\|\mathbf{x}\|^2 + \|\mathbf{y}\|^2).$$  We see that $$\|\mathbf{x}+\mathbf{y}\|^2 + \|\mathbf{x}-\mathbf{y}\|^2 = \langle\mathbf{x}+\mathbf{y},\mathbf{x}+\mathbf{y}\rangle + \langle\mathbf{x}-\mathbf{y},\mathbf{x}-\mathbf{y}\rangle,$$  which by linearity $$=\langle\mathbf{x},\mathbf{x}+\mathbf{y}\rangle + \langle\mathbf{y},\mathbf{x}+\mathbf{y}\rangle + \langle\mathbf{x},\mathbf{x}-\mathbf{y}\rangle - \langle\mathbf{y},\mathbf{x}-\mathbf{y}\rangle.$$  I've been trying to figure out how to go about this proof using linearity in the second argument of an inner product, but my textbook does not say that linearity necessarily holds in the second component. If it does, how would I go about the rest of this proof? If not, should I be potentially using some aspect of conjugate symmetry to prove this statement? How to create a hole in a polygon in QGIS? I'm trying to use the tool "delete ring" in order to create a hole in a polygon. The geometry of the hole is another feature of the same shapefile   I cannot manage to delete the part of the polygone. Does someone have a tutorial or some explanation? I would like to see everything on my computer screen in grayscale (like say the kindle screen). How do I do this? iPhone 7 Plus takes days to turn on showing Apple logo or black screen I’ve had this issue for months but in the last couple of days it’s got very very bad.  When my phone runs out of battery it needs like 2–3 days to turn back on. At the beginning of this problem the phone would need about 1h. Every time when my phone goes off again the time to switching on goes up.  What does this all look like? Well, when my phone died I put it on the charger, then the logo appears and goes off. When it goes off, a black screen pops out with a little white line on in it, then it turns on back to Apple logo. It keeps doing this until it turns on which is 1 or 2 even now 3 days.  I tried to restore it and also update it but nothing happens, literally nothing happened. How do I remove this wall plate with no visible screws? I'm amazed how complicated this wall plate is to remove. It is made of plastic and accommodates a phone jack and a coaxial cable. Please see the images that accompany this question. I've searched it thoroughly and there are no tabs anywhere on the face or edges to press in. There are no screws. I've pulled on it pretty hard, hoping that it would pop off, but if I pulled any harder it surely would break. Of course, I had the coaxial off while I tried to remove the plate. The brand name on the phone jack part is &quot;KRONE&quot;. Has anyone seen a wall plate like this? If so, how do you remove it? I have to say, I'm absolutely blown away by how ridiculously difficult this is. Any help would be appreciated. I'd like to be able to easily transfer large files wirelessly, fast, between Android devices - preferably without requiring root.  As a secondary objetive, it wouldn't hurt if the same solution could be used, to transfer files between the Android devices and a Windows PC.   Specifically, I'm trying to exchange files between my Nexus 7 (Android 4.2.2) and Samsung Galaxy S2 (Android 4.0.4).   Bluetooth is simply too slow, so that's out of the question Transfer via the Internet is also not an option, hence so is cloud-based solutions Only Nexus 7 supports NFC, so that's out too  looked promising and very simple, but does not work on "Devices that don't have WiFi Tethering setting, such as the Nexus 7"   Wi-Fi direct ( and up) seems to be a decent lowest common denominator between my two devices, however...  Galaxys S2's native Send via Wi-Fi Direct sees the Nexus, but seems to get stuck in the "Connecting..." most times. When there finally seems to be breakthrough, I get "Waiting..." and a spinning circle. Even if it worked, it would only allow me to send from the Galaxy S2 to the Nexus 7, as a similar option os not present on the Nexus 7.  J4velin's  is no longer available in the Play Store, with the following explanation:     WiFi Direct drivers are broken on many devices, which led to users leaving negative reviews for this app. As I don't see any sense in keeping a free app published when only getting 1-star-ratings (for an issue which only your device manufacturer can fix), the app is no longer available at the Play Store.   Nick Adams'  seems flaky at best. Invations from Nexus 7 to Galaxy S2 are never received. Invitations from Galaxy S2 are mostly received, but even when accepting promptly, the peers doesn't always show as connected. When they finally do, usually after quite a long wait, I can select a file to send but it's never transferred -  "Transfer failed" it says almost immediately in the notification bar.  budius inc's  is working slightly better, but still very unreliable. I actually managed to (occasionally) send files both ways, but never when attempting connection from the Nexus 7. To send from the Nexus 7 to the Galaxy S2, I had to go through this akward manoeuvre:   Share the file on the Nexus 7 via the WiFi Shoot intent Start the Receive WiFi Shoot app on the Galaxy S2 Invite the Nexus 7 from the Galaxy S2 (never the other way around!) Accept the invitation on the Nexus 7 Press the Shoot button on the Galaxy S2   Take the whole switching back and forth between devices, and garnish with random delays or failures in any step of the process...  Is there really no easy, reliable, fast way to transfer files directly between different Android devices?  Generally, my experience with Wi-Fi Direct is all but positive...   A device often won't even see a device lying next to it Sometimes, it will see the other device, only to have it disappear from the list, before I have the chance to connect When I do have a chance, invations are not realiably received (from Galaxy S2 to Nexus 7 mostly reliable, but never worked the other way around) When invitations are received (and accepted), a partnership rarely manages to be setup ("invited" or "connecting") And even when that happens, some apps can't seem to transfer files through it...   *Sigh*  Maybe J4velin's explanation pretty much sums up the sad state of Wi-Fi Direct on Android, which otherwise seemed as the best solution to my quest? If I remove Minecraft sound files from .minecraft/assets/objects, will Minecraft be unable to play them? In Minecraft, there are a lot of cool sounds. I decided to find there location and move them to my desktop. I have Ubuntu, and if when I remove them from that folder will Minecraft be unable to play them or is it smart enough to figure out that they are gone and download them again. Before minecraft was installed, it had to download the files. I even moved my favorite song (creative 6) from the sounds. The sounds are not labeled and have seemingly random names like b0b12118a97ddd733a50e9382e91a21652568641 and how will I know what to call them that will be recognized without digging through the index if Minecraft fails to download them? Or do I not have to worry because it will download them again upon launch?  Note: Why does it not label them and call them random names? I am using Sql Server 2008 on Small Business Server 2003; client is using WinXP.   I added a user to my Active Directory Security Group; Why can't this user immediately access the database? It seems there is a delay before the user is recognized in Sql Server.   I am using AD Security Groups for permissions expressly so that I don't need to add individual users in Sql Server. So effectively I don't need to do anything but add the user to the AD Security Group in order to grant access.  But for some reason Sql Server doesn't immediately recognize the addition. I've seen this a number of times. I add the user to the group but that user can't access data until the next day. It seems that it doesn't query the Active Directory in real time. Can you confirm that is so?  What do I need to do so that Sql Server "refreshes" the list of users from Active Directory? dpkg exit with error "cannot scan updates directory `/var/lib/dpkg/updates/': No such file or directory", how to fix it? Earlier, I had a problem with a package, and I (wrongly) ran this:  rm -r /var/lib/dpkg/*   See also .  Now when I try to upgrade, I get this:  E: Could not get lock /var/lib/dpkg/lock - open (11: Resource temporarily unavailable) E: Unable to lock the administration directory (/var/lib/dpkg/), is another process using it? masoud@masoud-PC:~$ sudo apt-get upgrade  E: Could not get lock /var/lib/dpkg/lock - open (11: Resource temporarily unavailable) E: Unable to lock the administration directory (/var/lib/dpkg/), is another process using it?   and when I use: sudo dpkg --configure -a   I get this:  dpkg: error: cannot scan updates directory `/var/lib/dpkg/updates/': No such file or directory     and for sudo apt-get upgrade -f get:  Reading package lists... Done Building dependency tree        Reading state information... Done Correcting dependencies... failed. The following packages have unmet dependencies:  ia32-libs : Depends: ia32-libs-multiarch but it is not installable  wine1.4 : Depends: wine1.4-i386 (= 1.4.1-0ubuntu5) but it is not installable E: Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages. E: Unable to correct dependencies How do you choose Spells Known when creating a new character above 1st level? Induction Proof that $x^n-y^n=(x-y)(x^{n-1}+x^{n-2}y+\ldots+xy^{n-2}+y^{n-1})$ This question is from [Number Theory George E. Andrews 1-1 #3].     Prove that $$x^n-y^n=(x-y)(x^{n-1}+x^{n-2}y+\ldots+xy^{n-2}+y^{n-1}).$$   This problem is driving me crazy. $$x^n-y^n = (x-y)(x^{n-1}+x^{n-2}y+\dots +xy^{n-2}+y^{n-1)}$$  $(x^n-y^n)/(x-y) =$ the sum for the first $n$ numbers and then I added $(xy^{(n+1)-2}+y^{(n+1)-1})$ which should equal $(x^{n+1}-y^{n+1})/(x-y)$ but I can't figure it out    This is a similar problem in the book and I tried this method but it wasn't working out      $\quad$Thereom $\bf1$-$\bf2$: $\,\,\,\,$ If $\,x$ is any real number other than $1$, then $$\sum_{j=0}^{n-1}x^j=1+x+x^2+\ldots+x^{n-1}=\dfrac{x^n-1}{x-1}.$$    $\quad$Remark: $\displaystyle\sum_{j=0}^{n-1}A_j$ is shorthand for $A_0+A_1+A_2+\ldots+A_{n-1}.$     $\quad$Proof: Again we proceed by mathematical induction. If $n=1$ then $\displaystyle\sum_{j=0}^{1-1}x^j=x^0=1$ and $(x-1)/(x-1)=1$. Thus the theorem is true for $n=1$.  $\quad$ Assuming that $\displaystyle\sum_{j=0}^{k-1}x^j=(x^k-1)/(x-1)$, we find that $$ \eqalign{ \sum^{(k+1)-1}_ {j=0}x^j &amp; = \sum^{k-1}_ {j=0}x^j+x^k=\dfrac{x^k-1}{x-1}+x^k \\ &amp;= \dfrac{x^k-1+x^{k+1}-x^k}{x-1}\\ &amp;= \dfrac{x^{k+1}-1}{x-1}. }$$   Hence condition $(\rm ii)$ is fulfilled, and we have established the theorem.    $\quad$Corollary $\bf1$-$\bf1$: $\,\,$ If $\,m$ and $n$ are positive integers and if $m&gt;1$, then $n&lt;m^n.$ I need a robust and simple way to remove illegal path and file characters from a simple string. I've used the below code but it doesn't seem to do anything, what am I missing?  using System; using System.IO;  namespace ConsoleApplication1 {     class Program     {         static void Main(string[] args)         {             string illegal = "\"M&lt;&gt;\"\\a/ry/ h**ad:&gt;&gt; a\\/:*?\"&lt;&gt;| li*tt|le|| la\"mb.?";              illegal = illegal.Trim(Path.GetInvalidFileNameChars());             illegal = illegal.Trim(Path.GetInvalidPathChars());              Console.WriteLine(illegal);             Console.ReadLine();         }     } } How to remove the top horizontal bar in fancyhdr? When using fancyhdr, how do you remove the top horizontal rule?  I do not want a header at all, just a footer.  This is what I do now:  \documentclass{article} \usepackage{fancyhdr} \pagestyle{fancy}  \lfoot{text} \cfoot{text 2} \rfoot{text 3}  \begin{document} Foo Bar \end{document} What is the most straight forward way to downgrade Firefox 57 to Firefox 56?   This is to have more time to wait for working replacements for legacy extensions. How do I play a sound in Octave? How to prove that $\mathbb{Q}$ ( the rationals) is a countable set I want to prove that $\mathbb{Q}$ is countable. So basically, I could find a bijection from $\mathbb{Q}$ to $\mathbb{N}$. But I have also recently proved that $\mathbb{Z}$ is countable, so is it equivalent to find a bijection from $\mathbb{Q}$ to $\mathbb{Z}$? Post Link for Tag Info Wiki's display text should be better than "unknown" The displayed text for a [Post Link] where the underlying Id corresponds to a Tag/Info Wiki (where the link redirects successfully) is just &quot;unknown&quot;. For example, if you've ever edited a tag wiki: . It would be nice if this could be better identified.