"Unable to start Minecraft Runtime Enviroment"

A couple of days ago I tried getting on Minecraft with a friend. They were running 1.14.2, and my Minecraft was last updated to 1.14. No big deal; I'll just create a new instance in 1.14.2.

When I did this, it said the latest version was 1.14. It said - I cannot remember how exactly - that it could not obtain versions, and on the news page it said I was offline when I clearly was not.

I decided to try and reinstall Minecraft.

So I went to the Windows uninstaller and uninstalled everything having to do with Minecraft. I then installed the Minecraft installer and installed Minecraft.
That was when I got the message "Unable to start Minecraft Runtime Environment, this is most likely caused by corruption. Please reinstall Minecraft".

I tried using the repair function in the installer to no avail.
So I tried going into %appdata% and manually removing the .minecraft folder, and also going to Program Files (x86) and removing anything with Minecraft in its name.
Then I reinstalled the installer, and tried again, but the issue recurred.
At that point, I searched the internet for fixes, and found and tried all of the following, followed by trying the installer again:

• Running everything as admin;
• Removing .minecraft (despite already having done this);
• Making sure I'd got the right version of Java;
• Reinstalling Java;
• Trying the older version of the launcher (when I tried this, the entire console was blank and it basically did nothing. I checked the log and everything - I'll provide the logs at the end of this post).

System specifications:

(Hardware capable of running things like GTA V)

Windows 10.0.17763 
Java version : jre1.8.0_211
Native log under %appdata% > .minecraft:

     Native Launcher Version: 432
            Operating System: Windows 10 Home
  Application Data directory: C:\Users\james\AppData\Roaming\.minecraft
             Executable Path: MinecraftLauncher.exe
           App Directory dir: C:\Program Files (x86)\Minecraft Launcher
         Game data directory: C:\Users\james\AppData\Roaming\.minecraft
                Launcher dir: C:\Program Files (x86)\Minecraft Launcher\game
                    Java dir: C:\Program Files (x86)\Minecraft Launcher\runtime\jre-x64
                  TmpDir dir: C:\Users\james\AppData\Local\Temp\MinecraftLauncher
                         x64: 1
 Using configuration at path: C:\Users\james\AppData\Roaming\.minecraft\launcher_profiles.json

    Could not get manifest from piston backend.
    Starting C:\Program Files (x86)\Minecraft Launcher\game\launcher.dll with 
C:\Program Files (x86)\Minecraft Launcher\runtime\jre-x64\bin\javaw.exe
    Couldn't load launcher core from 
C:\Program Files (x86)\Minecraft Launcher\game\launcher.dll: LoadErrorNotPresent

Log of the older launcher:

    [18:41:30 INFO]: Minecraft Launcher 1.6.89-j (through bootstrap 5) started on windows...
    [18:41:30 INFO]: Current time is Jun 12, 2019 6:41:30 PM
    [18:41:30 INFO]: System.getProperty('os.name') == 'Windows 10'
    [18:41:30 INFO]: System.getProperty('os.version') == '10.0'
    [18:41:30 INFO]: System.getProperty('os.arch') == 'amd64'
    [18:41:30 INFO]: System.getProperty('java.version') == '1.8.0_211'
    [18:41:30 INFO]: System.getProperty('java.vendor') == 'Oracle Corporation'
    [18:41:30 INFO]: System.getProperty('sun.arch.data.model') == '64'
    [18:41:30 INFO]: proxy == DIRECT
    [18:41:30 INFO]: JFX is already initialized
    [18:41:31 INFO]: Refreshing local version list...
    [18:41:31 INFO]: Refreshing remote version list...
    [18:41:31 ERROR]: Unexpected exception refreshing version list
    javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
        at sun.security.ssl.Alerts.getSSLException(Unknown Source) ~[?:1.8.0_211]
        at sun.security.ssl.SSLSocketImpl.fatal(Unknown Source) ~[?:1.8.0_211]
        at sun.security.ssl.Handshaker.fatalSE(Unknown Source) ~[?:1.8.0_211]
        at sun.security.ssl.Handshaker.fatalSE(Unknown Source) ~[?:1.8.0_211]
        at sun.security.ssl.ClientHandshaker.serverCertificate(Unknown Source) ~[?:1.8.0_211]
        at sun.security.ssl.ClientHandshaker.processMessage(Unknown Source) ~[?:1.8.0_211]
        at sun.security.ssl.Handshaker.processLoop(Unknown Source) ~[?:1.8.0_211]
        at sun.security.ssl.Handshaker.process_record(Unknown Source) ~[?:1.8.0_211]
        at sun.security.ssl.SSLSocketImpl.readRecord(Unknown Source) ~[?:1.8.0_211]
        at sun.security.ssl.SSLSocketImpl.performInitialHandshake(Unknown Source) ~[?:1.8.0_211]
        at sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source) ~[?:1.8.0_211]
        at sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source) ~[?:1.8.0_211]
        at sun.net.www.protocol.https.HttpsClient.afterConnect(Unknown Source) ~[?:1.8.0_211]
        at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(Unknown Source) ~[?:1.8.0_211]
        at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(Unknown Source) ~[?:1.8.0_211]
        at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source) ~[?:1.8.0_211]
        at sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(Unknown Source) ~[?:1.8.0_211]
        at com.mojang.launcher.Http.performGet(Http.java:54) ~[launcher.jar:1.6.89-j]
        at net.minecraft.launcher.updater.RemoteVersionList.getContent(RemoteVersionList.java:60) ~[launcher.jar:1.6.89-j]
        at net.minecraft.launcher.updater.RemoteVersionList.refreshVersions(RemoteVersionList.java:42) ~[launcher.jar:1.6.89-j]
        at net.minecraft.launcher.updater.MinecraftVersionManager.refreshVersions(MinecraftVersionManager.java:62) ~[launcher.jar:1.6.89-j]
        at net.minecraft.launcher.Launcher$2.run(Launcher.java:177) [launcher.jar:1.6.89-j]
        at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) [?:1.8.0_211]
        at java.util.concurrent.FutureTask.run(Unknown Source) [?:1.8.0_211]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) [?:1.8.0_211]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) [?:1.8.0_211]
        at java.lang.Thread.run(Unknown Source) [?:1.8.0_211]
    Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
        at sun.security.validator.PKIXValidator.doBuild(Unknown Source) ~[?:1.8.0_211]
        at sun.security.validator.PKIXValidator.engineValidate(Unknown Source) ~[?:1.8.0_211]
        at sun.security.validator.Validator.validate(Unknown Source) ~[?:1.8.0_211]
        at sun.security.ssl.X509TrustManagerImpl.validate(Unknown Source) ~[?:1.8.0_211]
        at sun.security.ssl.X509TrustManagerImpl.checkTrusted(Unknown Source) ~[?:1.8.0_211]
        at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(Unknown Source) ~[?:1.8.0_211]
        ... 23 more
    Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
        at sun.security.provider.certpath.SunCertPathBuilder.build(Unknown Source) ~[?:1.8.0_211]
        at sun.security.provider.certpath.SunCertPathBuilder.engineBuild(Unknown Source) ~[?:1.8.0_211]
        at java.security.cert.CertPathBuilder.build(Unknown Source) ~[?:1.8.0_211]
        at sun.security.validator.PKIXValidator.doBuild(Unknown Source) ~[?:1.8.0_211]
        at sun.security.validator.PKIXValidator.engineValidate(Unknown Source) ~[?:1.8.0_211]
        at sun.security.validator.Validator.validate(Unknown Source) ~[?:1.8.0_211]
        at sun.security.ssl.X509TrustManagerImpl.validate(Unknown Source) ~[?:1.8.0_211]
        at sun.security.ssl.X509TrustManagerImpl.checkTrusted(Unknown Source) ~[?:1.8.0_211]
        at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(Unknown Source) ~[?:1.8.0_211]
        ... 23 more
    [18:41:31 INFO]: Loaded 1 profile(s); selected 'jamesadam10'
    [18:41:31 INFO]: Refreshing auth...
    [18:41:31 INFO]: Logging in with access token

UPDATE:
I tried installing Minecraft on my laptop from the same site, and I got the exact same issue, leading me to believe that the site I used is dodgy. I'm going to try to find the proper site and see if that works. If it does, I will post about it, and I will include the website's address so that no one else has this issue.

Solution 1:

Restart your computer then start the launcher again.

I guess the installer should include a warning about unfinished installation and that a reboot is required...