Cannot play in older 1.17 snapshots

@Constantijn Hoogenstrijd the same thing happens to me and I believe everyone

@Constantijn yes since the 21wa11 is here it's impossible to run old versions 

The problem is the new snapshot doesn't allow to open the worlds saved in the older versions. Also playing on older snapshots has never been an issue before.

Everyone on my server is experiencing this issue and nobody can launch 21w08b. We just get this `sorry, unable to start Minecraft` red flag in the upper-right-hand corner. Some of us get no error at all, clicking Play simply does nothing.

Same with already configured 21w05b setup and most likely any snapshot other than the latest.

@MisterD no, this is the appropriate place. Mojang isn't exactly known for their sense of urgency though.

Tons of people are without the ability to play or log onto their server? No worries, we're Mojang. We don't care 🙂

Yeah, same deal for me. Same error logs, same launcher issue. Guess we're going to be playing some hardcore worlds on this version until they fix it. 

Reinstalling the game (from scratch) did not help. Updating and restarting my computer, drivers, java, and graphics card also did not help as well as running the launcher as an administrator and changing the version of the compatibility mode. The messages that the launcher tells me are: "Unable to get details," when selecting any version before 21w11a, and 1.16.5, as well as "Sorry, unable to start Minecraft," when trying to launch any other version besides 21w11a and the latest release (1.16.5). No amount of configuring the executable made any change. Even deleting the "latest Snapshot" folder in .minecraft/versions changed nothing, all the launcher did was redownload the folder. Creating and subsequently deleting the installations in the launcher did nothing. Signing out of the launcher and then signing back in did nothing. Changing accounts did not help. When opening the launcher the version selected is not the one that the launcher was closed with. Clicking the play button begins the loading process for about a second then it terminates, after having given the "Sorry, unable to start Minecraft" message. Even trying an older version of the launcher did nothing, the game simply would not start. All logs show missing sounds or premature stopping before the game stops loading except for version 1.16.5, the missing sounds for 21w11a are: 

[23:16:28] [Render thread/WARN]: Missing sound for event: minecraft:item.axe.scrape
[23:16:28] [Render thread/WARN]: Missing sound for event: minecraft:item.axe.wax_off
[23:16:28] [Render thread/WARN]: Missing sound for event: minecraft:item.honeycomb.wax_on

Then there are some shader errors:

[23:16:29] [Render thread/WARN]: Shader block could not find sampler named Sampler2 in the specified shader program.
[23:16:29] [Render thread/WARN]: Shader new_entity could not find sampler named Sampler1 in the specified shader program.
[23:16:29] [Render thread/WARN]: Shader new_entity could not find sampler named Sampler2 in the specified shader program.
[23:16:29] [Render thread/WARN]: Shader position_color_tex_lightmap could not find sampler named Sampler2 in the specified shader program.
[23:16:29] [Render thread/WARN]: Shader position_tex_lightmap_color could not find sampler named Sampler2 in the specified shader program.
[23:16:30] [Render thread/WARN]: Shader rendertype_translucent_no_crumbling could not find sampler named Sampler2 in the specified shader program.
[23:16:30] [Render thread/WARN]: Shader rendertype_armor_cutout_no_cull could not find sampler named Sampler1 in the specified shader program.
[23:16:30] [Render thread/WARN]: Shader rendertype_entity_solid could not find sampler named Sampler1 in the specified shader program.
[23:16:30] [Render thread/WARN]: Shader rendertype_item_entity_translucent_cull could not find sampler named Sampler1 in the specified shader program.
[23:16:30] [Render thread/WARN]: Shader rendertype_item_entity_translucent_cull could not find sampler named Sampler2 in the specified shader program.
[23:16:30] [Render thread/WARN]: Shader rendertype_entity_translucent_cull could not find sampler named Sampler1 in the specified shader program.
[23:16:30] [Render thread/WARN]: Shader rendertype_beacon_beam could not find sampler named Sampler2 in the specified shader program.
[23:16:30] [Render thread/WARN]: Shader rendertype_entity_alpha could not find sampler named Sampler1 in the specified shader program.
[23:16:30] [Render thread/WARN]: Shader rendertype_entity_alpha could not find sampler named Sampler2 in the specified shader program.
[23:16:30] [Render thread/WARN]: Shader rendertype_entity_alpha could not find uniform named ColorModulator in the specified shader program.
[23:16:30] [Render thread/WARN]: Shader rendertype_eyes could not find sampler named Sampler1 in the specified shader program.
[23:16:30] [Render thread/WARN]: Shader rendertype_eyes could not find sampler named Sampler2 in the specified shader program.
[23:16:30] [Render thread/WARN]: Shader rendertype_energy_swirl could not find sampler named Sampler1 in the specified shader program.
[23:16:30] [Render thread/WARN]: Shader rendertype_energy_swirl could not find sampler named Sampler2 in the specified shader program.
[23:16:30] [Render thread/WARN]: Shader rendertype_armor_glint could not find uniform named FogColor in the specified shader program.
[23:16:30] [Render thread/WARN]: Shader rendertype_armor_entity_glint could not find uniform named FogColor in the specified shader program.
[23:16:30] [Render thread/WARN]: Shader rendertype_glint_translucent could not find uniform named FogColor in the specified shader program.
[23:16:30] [Render thread/WARN]: Shader rendertype_glint could not find uniform named FogColor in the specified shader program.
[23:16:30] [Render thread/WARN]: Shader rendertype_glint_direct could not find uniform named FogColor in the specified shader program.
[23:16:30] [Render thread/WARN]: Shader rendertype_entity_glint could not find uniform named FogColor in the specified shader program.
[23:16:30] [Render thread/WARN]: Shader rendertype_entity_glint_direct could not find uniform named FogColor in the specified shader program.
[23:16:30] [Render thread/WARN]: Shader rendertype_text_see_through could not find sampler named Sampler2 in the specified shader program.
[23:16:30] [Render thread/WARN]: Shader rendertype_tripwire could not find sampler named Sampler2 in the specified shader program.
[23:16:30] [Render thread/WARN]: Shader rendertype_crumbling could not find sampler named Sampler2 in the specified shader program.

Then there are some spawning issues in Snapshot 21w11a:

[21:52:31] [Render thread/WARN]: Ambiguity between arguments [teleport, destination] and [teleport, targets] with inputs: [Player, 0123, @e, dd12be42-52a9-4a91-a8a1-11c01849e498]
[21:52:31] [Render thread/WARN]: Ambiguity between arguments [teleport, location] and [teleport, destination] with inputs: [0.1 -0.5 .9, 0 0 0]
[21:52:31] [Render thread/WARN]: Ambiguity between arguments [teleport, location] and [teleport, targets] with inputs: [0.1 -0.5 .9, 0 0 0]
[21:52:31] [Render thread/WARN]: Ambiguity between arguments [teleport, targets] and [teleport, destination] with inputs: [Player, 0123, dd12be42-52a9-4a91-a8a1-11c01849e498]
[21:52:31] [Render thread/WARN]: Ambiguity between arguments [teleport, targets, location] and [teleport, targets, destination] with inputs: [0.1 -0.5 .9, 0 0 0]

Thanks for fixing this issue!

Hooray! Thanks slicedlime and team!