Resource pack troubleshooting

Fabulously Optimized supports various OptiFine features, including resource pack extras. However, the implementation differs from mod to mod and some resource packs are accepted in OptiFine even if they are broken, so this page should help you fix some of those issues.

Older versions

Is the resource pack actually built for the version you're running? If not, check for the latest version or use a converter tool like this one or the official one.

Broken paths

If you see this message while activating a resource pack:

Contains broken paths

This means the resource pack maker is using spaces or other non-standard characters in the file or folder names.

If this is the case, the modpack will warn you and allow overriding it, but note that various glitches may occur (miscolored or invisible blocks, lightning issues, broken textures...).

To fix that, please tell the resource pack maker to only use the following characters in file/folder names: a-z0-9._-.

See also: Minecraft Wiki article about this

Fullbright

If you want to have game brightness at 100% where not usually expected, see your options below.

Works

• Night Vision potion

• Holding up a torch

• Dedicated mods that add fullbright

• Shaders (Iris or OptiFine) for fullbright

Does not work

• Resource packs that add fullbright ("core shaders")

• Editing options.txt directly (vanilla game restriction)

Disabling fog

If you'd like to disable fog, see your options below.

Works

• Fog setting in video settings (provided by the modpack)

• Dedicated mods that add fog toggles

• Shaders (Iris or OptiFine) for disabling fog

Does not work

• Resource packs that disable fog ("core shaders")

Invisible blocks

This may occur when the pack is using broken paths and is trying to change the models of some blocks, like chests.

Enhanced Block Entities

Enhanced Block Entities is the mod that makes various blocks faster on most versions of FO. Some optimizations may not be supported by your resource packs, so here's how to configure it:

1. Click Mods

2. Search for "Enhanced Block Entities", click the config button

3. Enable "Force Resource Pack Compatibility"

   • If that doesn't help or the option is not visible, disable any blocks that seem broken to you. Usually disabling Enhanced Chests is enough.

4. Click Done

Better Beds

Some versions of FO include Better Beds instead.

1. Close the game

2. Remove or disable the Better Beds mod from your launcher.

3. Start the game and see if it is fixed.

FastChest (FO 1.12.3 and older)

1. Click Mods

2. Search for "FastChest", click the config button

3. Disable the mod, click Done.

Core shaders/incompatible with Sodium

Resource packs may be incompatible with Sodium

Resource packs are incompatible with Sodium

Does the resource pack change the UI beyond usual means (e.g. rearrange HUD elements)? Does the resource pack change lighting or fog?

That means it may depend on core shaders, which are not fully supported on the modpack. When possible, always use dedicated mods instead.

Custom colors

Please ensure you're using FO 5.9.0 or newer; or FO 4.5.7 or older.

Custom entity models

Or "mobs with a custom shape".

Fresh Animations' latest version is fully supported.

If the entities are missing parts of their body, try this:

1. Click Mods

2. Search for "Entity Model Features", click the config button (top right, above Issues)

3. Set "Substitute missing model parts" to Yes

4. Click Save changes and Done

Issues and workarounds are tracked on the mod's Discord or GitHub.

Legacy versions - 4.6.0 and earlier

Partly supported. Resource packs that should work are discussed here (cem#9)

For Fresh Animations, try this version with the instructions below (discuss any issues here).

If your resource pack's entities are supported but are still not displayed correctly, you can try this:

1. Click Mods

2. Search for "Custom Entity Models", click the config button (top right, above Issues)

3. Set "Use model creation fix?" to No

4. Click Save & Quit and Done

5. In your world, hold down F3 (and Fn on laptops), press T

6. You'll see a short loading screen. After that, check if the models are displayed correctly.

7. If they still are not, set that setting back to Yes and disable your resource pack, wait for CEM to implement them.

   • Or if you want to continue using your resource pack without the models, disable the optifine setting in CEM to essentially disable the mod.

See also: a list of supported entity types and features.