[Info: 2019-06-30 09:26:29.6826916: main.cpp(214)] Native Launcher Version: 455
[Info: 2019-06-30 09:26:29.6829829: main.cpp(215)] Operating System: Windows 10 Home
[Info: 2019-06-30 09:26:29.6831273: main.cpp(216)] Application Data directory: C:\Users\lemon\AppData\Roaming\.minecraft
[Info: 2019-06-30 09:26:29.6831481: main.cpp(217)] Executable Path: MinecraftLauncher.exe
[Info: 2019-06-30 09:26:29.6831635: main.cpp(218)] App Directory dir: C:\Program Files (x86)\Minecraft Launcher
[Info: 2019-06-30 09:26:29.6831783: main.cpp(219)] Game data directory: C:\Users\lemon\AppData\Roaming\.minecraft
[Info: 2019-06-30 09:26:29.6831930: main.cpp(220)] Launcher dir: C:\Program Files (x86)\Minecraft Launcher\game
[Info: 2019-06-30 09:26:29.6832072: main.cpp(221)] Java dir: C:\Program Files (x86)\Minecraft Launcher\runtime\jre-x64
[Info: 2019-06-30 09:26:29.6832219: main.cpp(222)] TmpDir dir: C:\Users\lemon\AppData\Local\Temp\MinecraftLauncher
[Info: 2019-06-30 09:26:29.6832351: main.cpp(223)] x64: 1
[Info: 2019-06-30 09:26:29.6832518: LauncherConfiguration.cpp(229)] Using configuration at path: C:\Users\lemon\AppData\Roaming\.minecraft\launcher_profiles.json
[Warning: 2019-06-30 09:26:29.6834808: LauncherConfiguration.cpp(63)] Failed to get clientToken from configuration, launcher updater will fall back to using stable versions instead of controlled experiment versions.
[Info: 2019-06-30 09:26:29.8392368: LauncherConfiguration.cpp(140)] Deciding on update with strategy 0 and clientID 0
[Info: 2019-06-30 09:26:29.8392757: LauncherConfiguration.cpp(156)] Version of launcher-bootstrap is current, no action is necessary.
[Info: 2019-06-30 09:26:29.8392930: LauncherConfiguration.cpp(189)] Bootstrap is current
[Info: 2019-06-30 09:26:29.8394758: LauncherConfiguration.cpp(140)] Deciding on update with strategy 0 and clientID 0
[Info: 2019-06-30 09:26:29.8395111: LauncherConfiguration.cpp(156)] Version of launcher-core is current, no action is necessary.
[Info: 2019-06-30 09:26:29.8395390: LauncherConfiguration.cpp(189)] Bootstrap is current
[Info: 2019-06-30 09:26:29.8397213: LauncherConfiguration.cpp(140)] Deciding on update with strategy 0 and clientID 0
[Info: 2019-06-30 09:26:29.8397418: LauncherConfiguration.cpp(156)] Version of jre-x64 is current, no action is necessary.
[Info: 2019-06-30 09:26:29.8397559: LauncherConfiguration.cpp(189)] Bootstrap is current
[Info: 2019-06-30 09:26:29.8398075: StartLibrary.cpp(67)] Starting C:\Program Files (x86)\Minecraft Launcher\game\launcher.dll with C:\Program Files (x86)\Minecraft Launcher\runtime\jre-x64\bin\javaw.exe
[Info: 2019-06-30 09:26:29.8831575: StartLibrary.cpp(76)] Running launcher!
[Info: 2019-06-30 09:26:29.8850168: LauncherMain.cpp(71)] Running Launcher
[Info: 2019-06-30 09:26:29.8854214: NetQueue.cpp(202)] NetQueue: Initiating shutdown.
[Info: 2019-06-30 09:26:29.8862809: LauncherMain.cpp(143)] Launcher core version: 2.1.5387 (d5f0ae544bfc776d9523eef956933480a58d90e7)
[Info: 2019-06-30 09:26:29.8867951: GameVersionManager.cpp(70)] Looking for installed versions in C:\Users\lemon\AppData\Roaming\.minecraft\versions
[Error: 2019-06-30 09:26:29.8882775: LauncherController.cpp(446)] NO_USER_SELECTED
[Info: 2019-06-30 09:26:29.8888636: NetQueue.cpp(514)] NetQueue: worker thread started.
[Info: 2019-06-30 09:26:29.8921679: NetQueue.cpp(529)] NetQueue: Starting net action https://launchermeta.mojang.com/mc/game/version_manifest.json?_t=2019-06-30T09:26:29Z
[Info: 2019-06-30 09:26:29.9572162: LauncherAppBrowser.cpp(73)] Work dir is C:\Users\lemon\AppData\Roaming\.minecraft
[Info: 2019-06-30 09:26:29.9576226: ClientHandler.cpp(266)] Creating launcher window.
[Info: 2019-06-30 09:26:30.0469792: NetQueue.cpp(396)] NetQueue: Primary ip: 99.84.194.140, Url: launchermeta.mojang.com
[Info: 2019-06-30 09:26:30.0470215: NetQueue.cpp(467)] NetQueue: Action finished: https://launchermeta.mojang.com/mc/game/version_manifest.json?_t=2019-06-30T09:26:29Z
[Info: 2019-06-30 09:26:30.0470427: GameVersionManager.cpp(160)] Got available versions manifest from https://launchermeta.mojang.com/mc/game/version_manifest.json?_t=2019-06-30T09:26:29Z
[Info: 2019-06-30 09:26:30.0928936: LauncherAppRenderer.cpp(116)] Javascript bridge extended.
[Info: 2019-06-30 09:26:30.1643856: LauncherAppRenderer.cpp(230)] Context is null!
[Info: 2019-06-30 09:26:30.1680716: LauncherAppRenderer.cpp(230)] Context is null!
[Info: 2019-06-30 09:26:30.1946141: LauncherAppRenderer.cpp(230)] Context is null!
[Info: 2019-06-30 09:26:30.3374245: LauncherAppRenderer.cpp(278)] Creating renderer context...
[Error: 2019-06-30 09:26:31.5819711: LauncherController.cpp(322)] Failed to get clientToken from configuration, launcher updater will fall back to using stable versions instead of controlled experiment versions.
[Info: 2019-06-30 09:26:31.5820664: NetQueue.cpp(529)] NetQueue: Starting net action https://launchermeta.mojang.com/v1/products/launcher/a9ed4e847bec412e84bbdc95c11e7771218be683/windows-x86.json
[Info: 2019-06-30 09:26:31.5981619: NetQueue.cpp(396)] NetQueue: Primary ip: 99.84.194.140, Url: launchermeta.mojang.com
[Info: 2019-06-30 09:26:31.5982107: NetQueue.cpp(467)] NetQueue: Action finished: https://launchermeta.mojang.com/v1/products/launcher/a9ed4e847bec412e84bbdc95c11e7771218be683/windows-x86.json
[Info: 2019-06-30 09:26:31.5988735: LauncherAppRenderer.cpp(226)] Context is main frame of browser!
[Info: 2019-06-30 09:26:44.4821847: NetQueue.cpp(529)] NetQueue: Starting net action https://authserver.mojang.com/authenticate
[Info: 2019-06-30 09:26:46.0182619: NetQueue.cpp(396)] NetQueue: Primary ip: 158.69.199.196, Url: authserver.mojang.com
[Info: 2019-06-30 09:26:46.0183405: NetQueue.cpp(428)] NetQueue: Action failed with result "The requested URL returned error: 502 Bad Gateway" (22) : https://authserver.mojang.com/authenticate
[Info: 2019-06-30 09:26:46.0183723: NetQueue.cpp(467)] NetQueue: Action finished: https://authserver.mojang.com/authenticate
[Info: 2019-06-30 09:26:46.0185154: EndpointAPI.cpp(128)] Error: The requested URL returned error: 502 Bad Gateway, Code: 502
[Error: 2019-06-30 09:26:46.0185789: LauncherController.cpp(633)] CONNECTION_OFFLINE
[Info: 2019-06-30 09:26:46.0190739: LauncherAppRenderer.cpp(226)] Context is main frame of browser!
HELP PLEASE!
Fixed:
Head to C:\Windows\System32\drivers\etc\
Delete all host/hosts files.
The reason it didn't work is that the files had a code to make minecraft offline.