Console error:
[11:11:13] [Render thread/ERROR]: [Grind Enchantments] Error decoding config: No key consume_enchanted_item in MapLike[{"enabled":true,"cost_config":{"count_mode":"count_levels","cost_factor":1.0,"cost_offset":0.0}}]

To fix this issue, you'll have to edit the config (in .minecraft/config/grindenchantments.json) and add a consume_enchanted_item field to the disenchant object (with false as the value).

Or, if you haven't edited the config previously, you can also just delete that file. The mod should just regenerate it then.

Does it crash, or does it still use the default config in this case?

It does not crash.
No, we haven't edited it. Let me try re-generating the config.

Does it crash, or does it still use the default config in this case?

To fix this issue, you'll have to edit the config (in .minecraft/config/grindenchantments.json) and add a consume_enchanted_item field to the disenchant object (with false as the value).

Or, if you haven't edited the config previously, you can also just delete that file. The mod should just regenerate it then.

That has produced:
[11:18:26] [Render thread/INFO]: [Grind Enchantments] Writing default config.

That has produced:
[11:18:26] [Render thread/INFO]: [Grind Enchantments] Writing default config.

That means it writes back the default config to the file.

For why this is happening in the first place, it's because you had the mod in version 1.3 before (which introduced the config). In version 1.4, I added another option to it. So the mod was expecting that new field, which wasn't there because it was generated in the old version.

That also means that this error will re-appear every time a new config option is added.

Thank you, you have been very helpful. Greatly appreciated.

That has produced:
[11:18:26] [Render thread/INFO]: [Grind Enchantments] Writing default config.

That means it writes back the default config to the file.

For why this is happening in the first place, it's because you had the mod in version 1.3 before (which introduced the config). In version 1.4, I added another option to it. So the mod was expecting that new field, which wasn't there because it was generated in the old version.

That also means that this error will re-appear every time a new config option is added.