Experimental flag?

[Cassock]

Good evening. Trying to get a couple addons working for a peaceful world and some require the Holiday Creator setting to be enabled. This is grayed out for me (even as op). I didn't see an env for it, either. Any advice on enabling this?

[itzg]

And I don't see any mention of a server property, so I'm not sure how this can be enabled for the server container.

I'm going to convert this to a discussion so we can leave it around for people to answer.

[crocog1]

As per : https://old.reddit.com/user/ProfessorValko/comments/9f438p/bedrock_dedicated_server_tutorial/

You cannot use the following types of add-ons on your server:
Add-Ons purchased from the Minecraft Marketplace.
Add-Ons using Experimental Gameplay features such as custom mob entities, animations, data driven spawning, particles, functions.

And the Holiday Creator stuff is experimental I think?

[zentavr]

So how to enable "Holiday Creator Features" in this case? Which flag should be enabled?

[zentavr]

In order to to enable "Holiday Creator Features" add the key experiments/data_driven_items with 1 value. All the keys are here: https://wiki.bedrock.dev/nbt/experimental-education-edition.html

[josephdpurcell]

I'm still stuck trying to find a NBTEditor on Ubuntu or Mac. Here is a comment on one project with hope there is something simple I'm doing wrong Howaner/NBTEditor#8.

[josephdpurcell]

I was able to get jaquadro/NBTExplorer to build! See jaquadro/NBTExplorer#114 (comment).

However, that cannot read the level.dat file from Bedrock.

[josephdpurcell]

I also tried https://github.com/tryashtar/nbt-studio which wasn't able to run on Linux.

Good news, however! I also was unable to edit level.dat files from bedrock using https://marketplace.visualstudio.com/items?itemName=Misodee.vscode-nbt!

[Dabbadoeber]

This program can read the file : https://github.com/tryashtar/nbt-studio

Then i added these tags : https://wiki.bedrock.dev/nbt/experimental-education-edition.html

And was abble to add mods

[josephdpurcell]

I was unable to use nbt-studio on linux, but as an alternative the VSCode plugin works https://marketplace.visualstudio.com/items?itemName=Misodee.vscode-nbt

[josephdpurcell]

To enable experimental flags you must edit the world's level.dat file. The following instructions are for Bedrock. See itzg/docker-minecraft-server#2911 (reply in thread) for confirmation that Java uses different properties.

Background...

This was a HUGE pain to figure out.

The first problem was figuring out how to edit these NBT files. You can see my journey in comments over here: #373 (reply in thread). I don't know if I saw it in a comment or if it was just on whim that I thought to try the VSCode extension. I vaguely recall seeing it before but was turned off because it said "Viewer" and I incorrectly assumed it couldn't edit files.

The second problem was figuring out what exactly needed to be edited in these files. Fortunately, @itzg's comment over here #274 (comment) sparked the idea that I could use Minecraft Bedrock Launcher to create a world with the experimental flags enabled then inspect a vanilla level.dat file with the one that has the experiments enabled. Whoopeee!!! It worked! I was able to see exactly the flags needed.

Install a NBT editor. On Linux, the only one I could get to work was the VSCode extension NBT Viewer.

Stop the server. Make a backup of the data/ directory in case your world breaks.

Make a backup of your level.dat in case you need it:

$ cp 'data/worlds/Bedrock level/level.dat' ~/Downloads/level.dat.bak

Now, edit the real level.dat file in VSCode:

$ code 'data/worlds/Bedrock level/level.dat' 

Scroll down to "experiments" and click the + to expand the options. Double-click the 0 next to the experiments_ever_used and saved_with_toggled_experiments and replace the 0 with a 1 and then click "Confirm" like so:

Next we need to add flags to the "experiments" section. To do this, left click once on the word "experiments" then click "Add Tag". You should now see an input for Name and Value like so:

The flags you can add are all "Byte" types with a value of 1. Here is a map from the text displayed in the UI and the key/value you'll use in the file:

• Villager Trade Rebalancing: villager_trades_rebalance: 1
• Holiday Creator Features: data_driven_items: 1
• Custom biomes: data_driven_biomes: 1
• Upcoming Creator Features: upcoming_creator_features: 1
• Beta APIs: gametest: 1

Save the file.

Here is an example final result:

Start the server. You should see the experimental flags enabled in the UI like so:

Further reading:

• https://old.reddit.com/r/Minecraft/comments/11l5c4k/multi_server_with_120_additions/jbbxao3/ - Java instructions for enabling experimental flags
• Enabeling 1.21 Experimental Features docker-minecraft-server#2911 (reply in thread) - Java instructions confirmed to work
• https://minecraft.fandom.com/wiki/Bedrock_Edition_level_format - Documentation on the level.dat file which entirely omits details on experimental flags
• https://feedback.minecraft.net/hc/en-us/community/posts/360048142731-Experimental-MODE-FOR-Dedicated-servers-BEDROCK - People are upset that experimental mode is not available for dedicated servers, perhaps this is referring to the fact that the experimental flags are greyed out and you have to edit the level.dat file manually?

[josephdpurcell]

@Cassock After much research I have found an answer! See above.