This question has been asked before, but I have a different problem and the posted one is way outdated.  The problem is that I need an old and new firefox running at the same time to run a plugin called "Digital Pali Reader"  which will not work with the newer firefox. I followed the instructions from the website  and downloaded from:   It worked like a charm until I ran the new firefox.  Then it disabled the plugins which was the goal of running the old version.
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.
Are there any free/open source alternatives to Adobe After Effects? I've been a illustrator and graphic designer for a number of years and now I'm looking to go more into motion graphics and visual effects. Is there anything that is open source/free (not a demo, education version or trial) that is as complex and feature-rich as Adobe After Effects but for Linux? I've tried Cinlerra, kdenlive, openshot and Blender and whilst they are good at video editing (and 3d modelling in Blender's case) they fall short in effects and compositing features.  I've also tried , but the project recently closed and the last update was quite buggy.  Also,  doesn't work and hasn't been updated in many many years, so don't mention it ;-) Submitting a form by pressing enter without a submit button Why can't I destroy or place blocks? When I run sudo the terminal is stuck for a few seconds and then outputs an error message. My terminal looks like this:  ubuntu@(none):~$ sudo true sudo: unable to resolve host (none)   What can I do to solve it? Question: If $R$ is a finite boolean ring, then show $R \cong \mathbb Z_2 \times \mathbb Z_2 \times \cdots\times \mathbb Z_2$.   I know that   $\mathrm{char}(R) =2$  $R$ has $2^k$ elements for some $k$  (this is because, if $p\neq 2$ is a prime with $p\mid|R|$, then there exists a non-zero $x \in R$ s.t. $px=0$ and $p $ is odd $\implies x=0$, contradiction).   Does this suffice to answer my question? I want to set up a diary that compiles in two different orders: One is work by day, the other is work by project according to tags I give to the particular chunks of work I did each day.   For example, I write my diary as usual in work by day form:  2/2/15  -- bought a new screwdriver (tag: car maintainence)   -- scetched my plan for world domination (tag: world domination)  3/4/15  -- started studying physics (tag: world domination)  -- finished tax declaraction (tag: burocracy)   Compiling by project would yield tags as sections:  car maintainence    -- 2/2/15: bought a new screwdriver  world domination  -- 2/2/15: scetched my plan for world domination  -- 3/4/15: started studying physics  burocracy  -- 3/4/15: finished tax declaraction   I know this is pretty close to the literal programming paradigm the whole LaTex documentation follows: A code chunks in a document can be compiled to two different orders: For human understanding and for use by the machine. However, I want two human readable versions --say pdf-files-- as output. Is there some package that helps? What is a wave? Extreme cursor delay with Acer Aspire E15 on Ubuntu 16.04 Occasionally my laptop will enter a state where the cursor starts lagging so bad that it's unusable.  Oddly during this state, everything other than the cursor is still completely responsive.  I.e. anything that only involves the keyboard (opening a terminal, typing, etc) is unaffected.  Once it enters this state, on successive reboots and shutdowns it re-enters this state within seconds.  However, if I shutdown and leave it alone for a few minutes, it does not immediately re-enter this state.  Based on search results for "acer aspire ubuntu freeze" I have tried setting the intel_idle_max_cstate field in grub to 0, 1, and 2, but this did not seem to help.  To be clear - I am not experiencing any crashes, the system is completely responsive except for the cursor is delayed to the point where it would take several seconds to go from one edge of the screen to the other. NullReferenceException in Unity Show: $ f(a) = a,\ f(b) = b \implies \int_a^b \left[ f(x) + f^{-1}(x) \right] \, \mathrm{d}x = b^2 - a^2 $ Moving from HTTP to HTTPS in Google Search Console I'm moving from HTTP to HTTPS for my entire site. The site is currently added to Google Search Console (formerly Google Webmaster Tools) as www.example.com and all the pages are indexed without using SSL.  How do I go about moving to the new HTTPS URLs on Google Search Console?   Do I just submit an updated sitemap which has the HTTPS URLs or do I add a new site as https://www.example.com and submit the sitemap with HTTPS URLs? All current URLs are set to redirect to their HTTPS counterparts. Do I add multiple properties to Google Search Console? Apple Magic Trackpad multitouch configuration Converting WKT to SHP? What algorithm for a tic-tac-toe game can I use to determine the "best move" for the AI? Units and Nilpotents Beamer text and image on the same slide I would like to make a sum of all dropdown values into a label text box. I am using following formula, but I do not understand where am I going wrong. Can anyone assist? I have also added a screenshot if that helps anyhow. Note: scores is the table name the dropdown values feed from. Sum(scores, Dropdown3.Selected.Value + Dropdown3_1.Selected.Value + Dropdown3_2.Selected.Value) I'm trying to use Python to place a camera. I know the camera's location, and the forward and up vectors for the camera (i.e. the direction it's pointing and its orientation). How do I do this?  I know that it's possible to calculate a raw world matrix from the above information, which I can then apply to the camera, but I was rather hoping not to have to. Is there an easier way? I  and am I sometimes find myself writing something like this:     XXX is a project I admire and am very interested in.   The "I &#60;verb> and am &#60;something>" feels strange here. It somehow sounds more natural in the third person: "He admires and is very interested in...."  Am I just imagining things – is it OK to use this construction, or should I use something completely different? Array initialization syntax when not in a declaration