My problem is when in an open javafx project and try to run it without editing it, an error appear like this, and everything install for java FX.
What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?
Bluetooth disappeared in Windows 10 I have a Lenovo G580 laptop. In the past, using Windows 8, I could use Bluetooth to connect to other devices.  Installing Windows&nbsp;10, Bluetooth simply disappeared. I can't find anything related to Bluetooth in the Device Manager, also in Settings → Devices.  There is no Windows&nbsp;10 Bluetooth driver for my laptop.  What can I do? Rendering order in an Entity System Say I use a , and also inside Systems I hold lists of all entities that Systems are required to process.  How do I maintain this list of entities in desired rendering order, i.e. for a dumb 2D RenderingSystem?   I saw , and what they suggest is to do something like Z ordering - what I would probably do is just to store a "layer" int in DrawableComponent and then, inside RenderingSystem, just sort entities by mentioned "layer" whenever the entity list for RenderingSystem changes.  They also say we could just delete and recreate the entity whenever we want it on the top, but it seems too inflexible to me.  How is this problem usually solved? Can a java file have more than one class? Book series about preparation for a war at the Singularity I am looking for a book series (almost certainly a trilogy) that starts with some humans in a space station being abducted by a small funny-looking alien and taken to a prison planet. They find out that the way space travel works is by creating copies of the passengers, and the originals remained on the space station. This is actually good for the aliens since they believe every sentient being will resurrect at the Singularity and will be forced to fight a battle, so the more the merrier.  The one other detail I remember is that the world economy has a rampant inflation, so people take any cash they have at the end of the day and buy 20th-century memorabilia that doesn't devalue as much. Command for taking a screenshot to a new file I have enabled platform encryption at my DE and selected Case Subject, Description and Comments to be encrypted.  I have a created a sample case with these values:    And when I query from Developer Console it returns as follows:       How do I know, subject and description are encrypted at Rest? Is there any indicator which can confirm that this data is encrypted?   By the way, in case of File/attachment there is isEncrypted attribute is available which denotes the same as follows. I have a StreamReader object that I initialized with a stream, now I want to save this stream to disk (the stream may be a .gif or .jpg or .pdf).  Existing Code:  StreamReader sr = new StreamReader(myOtherObject.InputStream);    I need to save this to disk (I have the filename). In the future I may want to store this to SQL Server.   I have the encoding type also, which I will need if I store it to SQL Server, correct? Occasionally (very occasionally) when returning to the main page of a site by clicking on the logo I get the following message:     It was not possible to perform this tag search at this time due to an unexpected error.   This is odd because I'm not performing a tag search.  So far this has happened on both Movies &amp; TV and Cooking.  I have heard that others are getting this same message. Integral change that I don't understand If $f(t)$ is a Probability density function of a positive RV.  $\int_0^\infty\int_x^{\infty}f(t)dtdx$ Using fubini theorem should become $\int_0^\infty\int_0^{t}f(t)dxdt$  But why? Surely the answer is very simple but I don't see it. Fubini theorem allows the change of the order of integration. So it should become $\int_0^\infty\int_x^{\infty}f(t)dxdt$  but then I don't understand what meaning could have $\int_x^{\infty}dx$ Is Canon 60D still a decent camera? I have a Canon 60D, bought it back in 2013. Use it quite a while, but in past two-three years, I lost interest in photography. I will be going on a long trip this summer and would like to take a decent camera with me. Is Canon 60D still a decent one or I will be missing on features and upgrades comparing to the latest versions?  In terms of lenses I own Tamron 24-70 2.8 And Canon 100 2.8 Macro. How do you return from 'gf' in Vim I am using Vim for windows installed in Unix mode. Thanks to this site I now use the gf command to go to a file under the cursor.  I'm looking for a command to either:   return to the previous file (similar to Ctrl+T for ctags), or   remap gf to automatically launch the new file in a new window. How can I clone an ArrayList and also clone its items in Java?  For example I have:  ArrayList&lt;Dog&gt; dogs = getDogs(); ArrayList&lt;Dog&gt; clonedList = ....something to do with dogs....   And I would expect that objects in clonedList are not the same as in dogs list. Recover EXT4 partition I was trying to resize my EXT4 partition and something went wrong. I lost it. The space in once consumed is now being represented as Unallocated. How do I recover the partition? How does the Mounted Combatant feat interact with Infernal War Machines? find a sequence converging to zero but not the element of lp space for every 1<_p<infinity Unknown site on Android app When I select the unknown site (i.e. the meta sites) the app crashes.   I have a Samsung Note 5 and version 1.0.89 of the app. I have the following sequences $(a_n)$, $(b_n)=(a_{2n})$, and $(c_n) = (a_{2n-1})$.  I have to show that:   if $(b_n)$ and $(c_n)$ both convergence to $a$, then $(a_n)$ also converges to $a$; if $(a_n)$ converges then $(b_n)$ and $(c_n)$ also converge; there exist $(a_n)$ not converging but with $(b_n)$ and $(c_n)$ converging.   I am not sure how to solve this since I only know that $(b_n)$ > $(c_n)$ > $(a_n)$ on the terms how the sequences are defined. Two-Weapon Fighting & Bonus Actions During the latest gaming session our level 3 Rogue was Two-Weapon fighting with a Rapier in the main-hand and a scimitar in the off-hand.  At the completion of our gaming session I contested the application of the Two-Weapon fighting rules as it seemed unbalanced.  Once I got home I reviewed the PHB and various RPGStack and Reddit but couldn't find a concrete answer.  My interpretation of the PHB Reference rules below is that although any class/character can technically wield a weapon in their off-hand, only those who have been granted a Bonus Action for which no explicit bonus action have been defined would be allowed to actually attack.  So in the case of a Rogue the Bonus Actions granted under Cunning Action allow for specific actions (none of which are attack).  The alternate interpretation would be the rules under Two-Weapon Fighting, perhaps it should be written      you receive a bonus action to attack with a different light melee weapon that you’re holding in the other hand.   This would, in my opinion, explicitly grant the Bonus Action to any character/class who is Two-Weapon Fighting.  After thorough review does it boil down to application of the rules-as-written and determining a house-rule to apply in our campaign?    References  Page 189 of PHB : Bonus Actions  Various class features, spells, and other abilities let you take an additional action on your turn called a bonus action. The Cunning Action feature, for example, allows a rogue to take a bonus action.      You can take a bonus action only when a special ability, spell, or other feature of the game states that you can do something as a bonus   action. You otherwise don’t have a bonus action to take.   You can take only one bonus action on your turn, so you must choose which bonus action to use when you have more than one available. You choose when to take a bonus action during your turn, unless the bonus action’s timing is specified, and anything that deprives you of your ability to take actions also prevents you from taking a bonus action.  Page 96 of PHB  A Rogue receives cunning action at level 2, You can take a bonus action on each of your turns in combat.      This action can be used only to take the Dash, Disengage, or Hide action.   Page 195 of PHB  Two-Weapon Fighting (Combat Rules)  When you take the Attack action and attack with a light melee weapon that you’re holding in one hand, you can use a bonus action to attack with a different light melee weapon that you’re holding in the other hand. You don’t add your ability modifier to the damage of the bonus attack, unless that modifier is negative. If either weapon has the thrown property, you can throw the weapon, instead of making a melee attack with it.  Page 165 of PHB  Dual Wielder  (Feat)  You master fighting with two weapons, gaining the following benefits:   You gain a +1 bonus to AC while you are wielding a separate melee weapon in each hand. You can use two-weapon fighting even when the one-handed melee weapons you are wielding aren't light. You can draw or stow two one-handed weapons when you would normally be able to draw or stow only one. Is there an image editor like Windows' Paint for OS X? I tried out several image editors mentioned on  but some of them (like  and ) were very disappointing. These apps were too simple and low level.  What do you suggest for a (preferably free) image editor on OS X?  P.S: I was using  on Linux and also know that it was released for OS X too, but I want to find new good applications. Why couldn't Voldemort view the prophecy without Harry's help?