I try to launch Minecraft with forge 1.16.3 (no mods installed yet) on a mac and I get this error:

                           

                                                ERROR

                                           Game crashed

 An unexpected issue occurred and the game has crashed. We’re sorry for the

                                           inconvenience.

                                            Exit Code: 0

[23Feb2021 15:45:45.763] [main/INFO] [cpw.mods.modlauncher.Launcher/MODLAUNCHER]: ModLauncher running: args [--username, Foxes_Rule, --version, 1.16.3-forge-34.1.42, --gameDir, /Users/todd/Library/Application Support/minecraft, --assetsDir, /Users/todd/Library/Application Support/minecraft/assets, --assetIndex, 1.16, --uuid, 120b4253bc984d2c85c370deb227395e, --accessToken, ❄❄❄❄❄❄❄❄, --userType, mojang, --versionType, release, --launchTarget, fmlclient, --fml.forgeVersion, 34.1.42, --fml.mcVersion, 1.16.3, --fml.forgeGroup, net.minecraftforge, --fml.mcpVersion, 20201025.185957]
[23Feb2021 15:45:45.767] [main/INFO] [cpw.mods.modlauncher.Launcher/MODLAUNCHER]: ModLauncher 8.0.6+85+master.325de55 starting: java version 1.8.0_74 by Oracle Corporation
[23Feb2021 15:45:45.781] [main/WARN] [cpw.mods.modlauncher.SecureJarHandler/]: LEGACY JDK DETECTED, SECURED JAR HANDLING DISABLED
[23Feb2021 15:45:46.012] [main/INFO] [net.minecraftforge.fml.loading.FixSSL/CORE]: Added Lets Encrypt root certificates as additional trust
[23Feb2021 15:45:46.067] [main/INFO] [mixin/]: SpongePowered MIXIN Subsystem Version=0.8.2 Source=file:/Users/todd/Library/Application%20Support/minecraft/libraries/org/spongepowered/mixin/0.8.2/mixin-0.8.2.jar Service=ModLauncher Env=CLIENT
[23Feb2021 15:45:47.591] [main/FATAL] [net.minecraftforge.fml.loading.FMLCommonLaunchHandler/CORE]: Failed to find forge version 34.1.42 for MC 1.16.3 at /Users/todd/Library/Application Support/minecraft/libraries/net/minecraftforge/forge/1.16.3-34.1.42/forge-1.16.3-34.1.42-universal.jar
[23Feb2021 15:45:47.592] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1052]: java.lang.RuntimeException: Missing forge!
[23Feb2021 15:45:47.592] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1052]:     at net.minecraftforge.fml.loading.FMLCommonLaunchHandler.validatePaths(FMLCommonLaunchHandler.java:118)
[23Feb2021 15:45:47.593] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1052]:     at net.minecraftforge.fml.loading.FMLLoader.setupLaunchHandler(FMLLoader.java:199)
[23Feb2021 15:45:47.593] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1052]:     at net.minecraftforge.fml.loading.FMLServiceProvider.initialize(FMLServiceProvider.java:94)
[23Feb2021 15:45:47.593] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1052]:     at cpw.mods.modlauncher.TransformationServiceDecorator.onInitialize(TransformationServiceDecorator.java:68)
[23Feb2021 15:45:47.594] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1052]:     at cpw.mods.modlauncher.TransformationServicesHandler.lambda$initialiseTransformationServices$7(TransformationServicesHandler.java:107)
[23Feb2021 15:45:47.594] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1052]:     at java.util.HashMap$Values.forEach(HashMap.java:972)
[23Feb2021 15:45:47.595] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1052]:     at cpw.mods.modlauncher.TransformationServicesHandler.initialiseTransformationServices(TransformationServicesHandler.java:107)
[23Feb2021 15:45:47.595] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1052]:     at cpw.mods.modlauncher.TransformationServicesHandler.initializeTransformationServices(TransformationServicesHandler.java:59)
[23Feb2021 15:45:47.595] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1052]:     at cpw.mods.modlauncher.Launcher.run(Launcher.java:76)
[23Feb2021 15:45:47.596] [main/INFO] [STDERR/]: [java.lang.ThreadGroup:uncaughtException:1052]:     at cpw.mods.modlauncher.Launcher.main(Launcher.java:66)
 

I downloaded the 1.16.3 - 34.1.42 from:

http://files.minecraftforge.net/maven/net/minecraftforge/forge/index_1.16.3.html

Then I just opened the .Jar file and pressed install.

By "what launcher" what do you mean? I use the normal Minecraft: Java Edition if that's what you mean.

Same things happens