The original FTB Ultimate for MC 1.4.7 crashes during startup with new versions of Java. This applies to any 1.4.7 modpack including Forestry or Railcraft. A crash might look like the following:

[SEVERE] [Railcraft] The mod Railcraft is expecting signature a0c255ac501b2749537d5824bb0f0588bf0320fa for source railcraft.jar, however there is no signature matching that description
[SEVERE] [Railcraft] Tampering Detected. Please re-download Railcraft.

1. Download this file, name it java.security and save it in the instances base folder (the .minecraft folder)
2. Add the following Java argument to your game: -Djava.security.properties=java.security

Copied from http://code.lancepollard.com/complete-list-of-html-meta-tags/

<meta charset='UTF-8'>
<meta name='keywords' content='your, tags'>
<meta name='description' content='150 words'>
<meta name='subject' content='your website's subject'>
<meta name='copyright' content='company name'>

1. http://stackoverflow.com/questions/804115 (rebase vs merge).
2. https://www.atlassian.com/git/tutorials/merging-vs-rebasing (rebase vs merge)
3. https://www.atlassian.com/git/tutorials/undoing-changes/ (reset vs checkout vs revert)
4. http://stackoverflow.com/questions/2221658 (HEAD^ vs HEAD~) (See git rev-parse)
5. http://stackoverflow.com/questions/292357 (pull vs fetch)
6. http://stackoverflow.com/questions/39651 (stash vs branch)
7. http://stackoverflow.com/questions/8358035 (reset vs checkout vs revert)

1. This is a numbered list.

2. I'm going to include a fenced code block as part of this bullet:

   Code
   More Code
   

As this is not an official way of installing Arc, if you encounter any issues do NOT report them to the developers, they did not intend for people to be running Arc on Windows 10.

This guide is a bit more manual since I wanted to respect the developers' wishes and not directly link any downloads to the beta of Arc.

I don't know how this will work with updates, you may just need to redo the process to update it, but I'm not sure

1. Install this font: https://aka.ms/SegoeFluentIcons (this fixes the icons since Windows 10 doesn't have this font installed by default)
2. Download the Arc appinstaller and open it in notepad/some other text editor
3. Copy everything inside and paste it into this website: https://codebeautify.org/xmlviewer (this is optional, but it makes reading and copying from the file easier)
4. Find the mainpackage @Uri, it should end in Arc.x64.msix, and open that in a new tab. It should download that msix file.

SWAP memory is basically parts of memory from the RAM (Random Access Memory) that enables an operating system to provide more memory to a running application or process than is available in physical random access memory (RAM). So if the physical memory (RAM) is full, we can use SWAP partition for extra memory resources. It is useful if we have low memory on our machine.

sudo dphys-swapfile swapoff