I'm playing Minecraft in Survival, and no hostile mobs are spawning! This has been happening for the past week or so. I also tried Creative mode (superflat) and mobs are spawning there.  What would cause mobs to stop spawning in Survival?  Details:   Minecraft 1.7.2 Using Rei's mini map mod Windows Vista Created a new super flat world (creative) and mobs spawn
I have just updated to Minecraft 1.7.4 and now all of a sudden there are barely any mobs spawning.  I checked to make sure that I was in normal difficult and I saw 1 creeper but that is all.  Also I tried different difficulties. Another thing - mobs seem to to spawn normally in the nether and all other mobs except aggressive mobs spawn like they should.  Please if you know how to fix this, please help!
Unable to edit my response to a locked question The image is broken in my  to the "favorite programmer cartoon" question. I'd be happy to fix this, but I can't (not enough rep? not a moderator?).  Here's the image in the Internet Archive: $a, b, c$ are positive real numbers.   Prove that $$8abc\le (a+b)(b+c)(c+a)$$  I haven't really gotten anywhere, just tried to open up $(a+b)(b+c)(c+a)$ and got null. postfix fails to send mail with "fatal: unknown service: smtp/tcp" From a link from the question  to the HP Wikia, I started mulling over something I read about Voldemort and the "regeneration" potion (not a canon potion, but I'll use it for lack of a better way of describing it. . .) and would really like to know:  How did Voldemort drink the regeneration potion to turn his body into the grotesque childlike form we see in Goblet of Fire while he was still in a "mangled spectral state"?  Spectres (i.e. spirits or ghosts) are non-corporeal; they obviously can't consume food or drink liquids. So, how did Voldemort overcome this difficulty and manage to drink the regeneration potion? Why Does the Transaction Log Keep Growing or Run Out of Space? In Avatar: The Last Airbender, Aang's eyes glow when he goes into the Avatar State. This seems to be the case with all Avatars, but Aang and the other airbending Avatars tattoos glow too.      Is there any reason for why airbending Avatars tattoos glow as well as their eyes? $1 \leq z \overline {z} \leq 4$ and $|\Im(z)|&lt;\Re (z)$  How can I solve this system of inequalities? ($\Im$ is the imaginary part and $\Re$ is the real part of a complex number).  I have tried so far: $z=x+yi$ and then I get $1 \leq x^2+y^2 \leq 4$ and $ |y|&lt;x$. How can I solve this? Can we some how use color labels on icons like OS X?  Something like this: Is cross-posting a question on multiple Stack Exchange sites permitted if the question is on-topic for each site? It is possible to migrate a question from one Stack Exchange site to another by closing, but if I have a question that I think is on-topic for multiple Stack Exchange sites, is it OK to post it on both (multipost)?   For example, I have a question that's earned me the tumbleweed badge on SO and I'm not sure what the best thing to do with it is. It's about a web server so it might be answerable on Server Fault but it's really more of a programming thing, hence the posting the question on Stack Overflow.    Is there any way to make the question visible on multiple sites (crosspost) and then accept the answer wherever it came from? How do I create a decimal field in Access with Alter Table? scp copy over ssh doesn't work - permission denied error, please? Makeindex error when ! used in \index in align environment See MWE below. The symbol ! in the \index causes an error. This is only the case in align environments (not in equation). So it seems to have to do something with amsmath. If ! is put in an \mbox there is no error. But then of course the font size is not adjusted to subindices. Curiously enough, \index{$C_{K!!}$} (two exclamation marks) doesn't cause any error.    \documentclass{article} \usepackage{amsmath} \usepackage{imakeidx} \makeindex \begin{document} \begin{align} y\index{$C_{K!}$} \end{align} \printindex \end{document}     Any solutions suggested? How can I make a time delay in Python? I would like to know how to put a time delay in a Python script. Where can I find historical data on arrival and departure times of a particular flight? Where can I find historical data on flights, specifically Delta international flights?  I need to find out about cancellations, diversions and any other flight data pertaining on particular route at a given time.  This source has to be official and stand up to legal scrutiny. Integrals of Pullbacks I want to loop over the contents of a text file and do a search and replace on some lines and write the result back to the file. I could first load the whole file in memory and then write it back, but that probably is not the best way to do it.  What is the best way to do this, within the following code?  f = open(file) for line in f:     if line.contains('foo'):         newline = line.replace('foo', 'bar')         # how to write this newline back to the file Ideals in ring of continuous functions $\mathcal{C}[0,1]$ ... NBHM- Algebra I would like to compile all questions I have encountered with Ideals in the ring $\mathcal{C}[0,1]$ of all continuous real valued functions and ask if there are any gaps.  Question is to see if :     the ideal $\mathcal{I}=\{f\in \mathcal{C}[0,1] : f(0)=0\}$ is maximal ideal in the ring $\mathcal{C}[0,1]$ of all continuous real valued functions.   What I have done so far is :  consider $\eta :\mathcal{C}[0,1]\rightarrow \mathbb{R}$ where $f\rightarrow f(0)$   $Ker (\eta) = \{ f\in \mathcal{C}[0,1] : f(0)=0\}$  I could see that for each $r\in \mathbb{R}$, I would set $f$ such that $f(x)=x+r$  So, $\eta$ is surjective.  So, I would get $\mathcal{C}[0,1]/\mathcal{I}\cong \mathbb{R}$  As $\mathbb{R}$ is a field so ia the quotient $\mathcal{C}[0,1]/\mathcal{I}$ which means that $\mathcal{I}$ is an ideal in $\mathcal{C}[0,1]$.    Now Another Question on same idea :  Question is to see if :     the ideal $\mathcal{I}=\{f\in \mathcal{C}[0,1] : f(0)=f(1)=0\}$ is maximal ideal in the ring $\mathcal{C}[0,1]$ of all continuous real valued functions.   I thought of using same ideas as above but i am unable to choose perfect $\eta$  I believe that this is not even a prime ideal..  I set  $f(x)=x$ and $g(x)=x-1$ and consider $f(x)g(x)=(x)(x-1)$ then,   $(fg)(0)=f(0)g(0)=0.(-1)=0$   $(fg)(1)=f(1)g(1)=1.0=0$  So, $fg\in \mathcal{I}=\{f\in \mathcal{C}[0,1] : f(0)=f(1)=0\}$ but the neither $f$ nor $g$ is in $\mathcal{I}$.    I have two questions:   I see that $0$ does not play any role in the question $\mathcal{I}=\{f\in \mathcal{C}[0,1] : f(0)=0\}$ I mean I would have same case if i replace $0$ by any real number.  So, I would like to say that $$\mathcal{I}=\{f\in \mathcal{C}[0,1] : f(r)=0\}$$  is a maximal ideal in the ring $\mathcal{C}[0,1]$ of all continuous real valued functions.  And one more thing I would claim is that      If the collection $\mathcal{I}$ is such that all elements of $\mathcal{I}$ has more than $1$ common zero then $\mathcal{I}$ is not a maximal ideal and not even a prime ideal..   I would like to learn more about this kind of ideals in $\mathcal{C}[0,1]$.  I would be thankful if some one can assure that what  have done is sufficient to conlcude what i have concluded and I would be thankful if some one can suggest some material to read regarding this.  Thank you I install virtualBox on Ubuntu 16.04, but after install and create new virtual Host shows this error:     Kernel driver not installed (rc=-1908)      The VirtualBox Linux kernel driver (vboxdrv) is either not loaded or there is a permission problem with /dev/vboxdrv. Please install virtualbox-dkms package and load the kernel module by executing  modprobe vboxdrv       as root. If it is available in your distribution, you should install the     DKMS package first. This package keeps track of Linux kernel changes and   recompiles the vboxdrv kernel module if necessary.  where: suplibOsInit what: 3 VERR_VM_DRIVER_NOT_INSTALLED (-1908) - The support driver is not installed. On linux, open returned ENOENT.     How to address this modprobe vboxdrv error? No 'Open with' option to open/run jar file with openjdk How to call a function in a Twig file