Object reference not set to an instance of an object in VS 2010
What is a NullReferenceException, and how do I fix it?
Example of non-isomorphic structures which are elementarily equivalent My son is going on 5 and starting to learn a lot about how we're created. I've been with my husband for 10 years, but nearly 6 years ago I had no other choice but to move 1000 miles away and after trying the long distance thing it didn't work so we split up.   I ended up going through a rough patch and started dating an abusive jerk. After a year I was pregnant. He threatened me trying to force me to have an abortion and I refused. His grandmother was chief of police and he scared me into moving back to Florida.  Eventually, when I was 4 months along in my pregnancy my husband and I picked up right where we left off. He loved me so much and accepted our son as if he was his own and has done an amazing job at raising him.   He enrolled in college while I was pregnant, got us a house and went above and beyond to care for us both (as after giving birth I became very ill due to rare brain and spine conditions). I've always tried to do right by my son. Since day one, even while with my husband, I tried to keep the sperm donor involved. But he wanted no part of his son.  My husband stepped up when the biological father refused. The biological father would pretend that he cared, only to tell me he never cared about him anyway and was just trying to manipulate me into stopping child support (which I did anyway after the first year: I felt it wasn't right to take his money when my son had a dad who loved, supported and wanted him from the beginning).  This is a very long story so I'll try and make it not so much of a novel. The sperm donor has made it very clear he wants nothing ever to do with my son. My husband has been Dad since the moment my son entered this world. I've always planned to tell my son as early as possible. I think now, or in a few years, it won't be as hard on him compared to us telling him when he's a teen and who knows how he'd handle it.   I just don't know what to do. We have an extremely happy loving family. My son adores his dad. We never argue, we have a very happy non-dysfunctional marriage. I just feel we have a very special family. But I refuse to lie to my son. What if we wait and someone else maliciously tells him? Or if, when he's older and finds out, he spirals out of control?  I'm so confused, I just want to do the right thing and desperately need advice. Especially from others who have been through similar circumstances. We're planning on meeting with therapists and I guess child development specialists, if someone could also point me in the right direction for what type of doctor is best suited in this situation.   Also my son is very happy. He has a wonderful life and I feel as if he would do fine, knowing how much he loves his dad and just beginning to really grasp the concept of life. I don't think it would change anything for him, if that makes sense. I've been worrying over this for 5 years and really need some answers! Since  and  you can get into a situation where your max HP is zero due to leveling up… what happens next?  What happens when your max HP is 0 because you leveled up with a negative Constitution modifier? Are you dead, unconscious, or what, and where do the rules say this? (The  assumes death, but that isn't established as fact anywhere yet.) These badges were only recently added to StackExchange. I would like to know if there is any way I can find out how many more questions I should ask to get these badges.   For e.g. like the counters for the review-related badges: Prove that any finite group $G$ of even order contains an element of order $2.$ I have a beamer frame with about 150 slides on it.  I want article and handout mode to only show frame 92.    Reading section 8.6.2 of the beamer manual it seems like I should be able to do something like  \begin{frame}&lt;handout:92&gt; ... \end{frame}   but that seems to have no effect--all 150 slides are set in handout mode, overlaying (making the result unreadable).  I have gotten the effect I want by taking all commands within the frame that have an overlay specification and adding "| handout:0" to make them not appear in handout mode.  Annoying, but works.  But for my 150-slide frame the different slides are generated by a PGF \foreach loop so I can't code slide 92 differently from the rest.  But can I do this at the frame's overlay specification?  It seems that the frame's overlay spec really acts differently from other commands.  If I only do  \begin{frame}&lt;92&gt;...\end{frame}   then I get only slide 92 in beamer mode but all slides in article or handout mode. Since many users are facing the NullReferenceException: Object reference not set to an instance of an object error in Unity, I thought that it would be a good idea to gather from multiple source some explanation and ways to fix this error.  Symptoms I am getting the error below appearing in my console, what does it mean and how do I fix it?  NullReferenceException: Object reference not set to an instance of an object What is the EV scale? I have seen an "EV" (exposure value) scale that's sometimes used to express a camera's exposure settings, or scene brightness. How exactly does this scale work? Could I have a hint for testing the convergence of the following series please?  $$\sum_{n=2}^\infty\frac{1}{(\ln n)^{\ln n}}$$  I am very appreciative for your help. Casting two cantrips, both modified by metamagic? Can you cast one cantrip, modifying it with "Twinned Spell" (Fire Bolt) to target 2 creatures, and then cast another cantrip as a Bonus Action (Fire Bolt), using "Quickened Spell" to target one of the previous creatures or another creature? I always know that the natural logarithm $\log_e$ is the inverse of the exponential function $e$, but to my surprise when reading elementary functions in complex analysis, I discover that that is not always true. $$\log(e^z)=z+2k\pi i$$  My question here is that, why is the above expression true? What is a word for a person with more expertise (in certain field) than an intermediate but less so than an expert? I'm using Ubuntu 11.04 and I want to free up some space in my root directory, which is overloaded. I especially want to change the path used for installing applications (they are getting installed directly to the root drive).  Another consideration is that I'm working on a MySQL database server. The server is installed in the root directory itself, so I don't want to  risk losing any data.  Please give me some tips to help sort out this problem. How to prove that $\lim \frac{1}{n} \sqrt[n]{(n+1)(n+2)... 2n} = \frac{4}{e}$ I'd like a hint to show that:  $$\lim \frac{1}{n} \sqrt[n]{(n+1)(n+2) \cdots 2n} = \frac{4}{e} .$$  Thanks. So from what I remember it was on cable TV. The main hero was a TV actor zapped to a alien planet. It had a evil overlord with a virgin priestesses. She wants to get laid but he refuses because the next priestesses is only three. Regardless it's a parody things include a man who was maimed by the evil overlord wants revenge the hero eventually screws the virgin priestesses it cuts to scenes of a train going into a tunnel and a volcano erupting. Distance learning: taken seriously? I'm currently in the first year of a six year bachelor's degree aiming for astrophysics. The course is a home/distance learning setup run by the Open University. While I am enjoying it thoroughly, I am aware of the academic politics that can dog professional science. So my question is thus: Upon soldiering on with the degree, then masters, and then PhD, will I be taken seriously within a professional setting given my inability to reference a leading university for my education? Will the format for my studying be "pitied"?   Edit: I suppose a bit more info may help. I'm 27,wife, 2 children, and I currently work as a full time chef, and self employed part time IT technician. I flunked my GCSEs, with no further education. The past 3 years have been a revelation for me, and I have discovered a before unexperienced love for academia; specifically, physics and astronomy. Last year I completed a 1 year OU maths brush up course, which at the time I really struggled with. This year I had a bout of madness and took the plunge for a BSc degree in astronomy. I am now loving the math within the physics so far (yet to hit calculus though!)  PhD, and even masters, is a long way off.  Also, since this original post I've improved my understanding of what a PhD actually entails. So I realise that if I get there, it may well not have anything to do with the OU!     It occurs to me that a lot of my initial queries could have been avoided with a better understanding of the educational and qualification system itself. I now have a greater appreciation as to what a PhD actually is, realising that its a long way off and not necessarily needed for a fulfilling career in research.  I think trying to repair my broken education and fight my way into a worthwhile (and productive!) career is enough of challenge at the moment. There will be plenty of time later for worries concerning doctorates.  It is good to hear that there is at least an open mind towards distance educated professionals.   As has been said, if you've got it, you've got it - you just have to be ready to prove it. Use /testfor to make a custom command Basically, I'm trying to recreate the Faction plugins /f map in my single-player without mods as my PC doesn't run them very well. (I know it sounds strange.) I am trying to use the /testfor to test if I have written '/f map' in chat, and if I have, it would show me a custom generated map. I don't know how to word this better xD Essentially what I want is for it to test if I have written a command in chat, and if I have, display something. I just flagged a comment as "obsolete" in . To my surprise, it was deleted immediately, just after pressing "Flag Comment".  Now I see it in my flag summary as helpful:        Does this mean that obsolete flags are somehow handled automatically? I went through  but could not find any description on this. I have a raster image (Sentinel-2 band 4) and a shapefile covering the same area than the image (same projection and extension). The shapefile has different polygons which are agricultural fields.   I want to create a new file where, for each polygon, the mean value of the pixels that are inside it is calculated.  Could you please help me to find an appropriate R code for that? How can I install apt packages non-interactively? If I run:  sudo apt-get --yes install postfix    or  sudo bash -c 'yes | apt-get --yes install postfix'   an interactive prompt appears to configure postfix. I need to automate the installation of postfix (I can modify the configuration files after the install).  Is there some magic that lets me install postfix (and other package) without human intervention?