Error while trying out the NES feature

[ammen99]

Hi all, I am trying out the new NES feature and after updating the plugin and enabling it, I am getting the following errors:

2025-10-17 15:27:09.142 [212] [ERROR]: LSP message: [Error: Failed to load from BPE encoder file stream: Error: ENOENT: no such file or directory, open '/home/ilex/.local/share/nvim/lazy/copilot.lua/copilot/js/o200k_base.tiktoken'
    at loadTikTokenBpe (/home/ilex/.local/share/nvim/lazy/copilot.lua/copilot/node_modules/@microsoft/tiktokenizer/dist/tikTokenizer.js:23:15)
    at new TikTokenizer (/home/ilex/.local/share/nvim/lazy/copilot.lua/copilot/node_modules/@microsoft/tiktokenizer/dist/tikTokenizer.js:72:69)
    at createTokenizer (/home/ilex/.local/share/nvim/lazy/copilot.lua/copilot/node_modules/@microsoft/tiktokenizer/dist/tokenizerBuilder.js:259:26)
    at t.init (/home/ilex/.local/share/nvim/lazy/copilot.lua/copilot/node_modules/@vscode/chat-lib/src/_internal/platform/tokenizer/node/tikTokenizerImpl.ts:37:21)
    at W1e.doInitTokenizer (/home/ilex/.local/share/nvim/lazy/copilot.lua/copilot/node_modules/@vscode/chat-lib/src/_internal/platform/tokenizer/node/tokenizer.ts:274:41)
    at W1e.ensureTokenizer (/home/ilex/.local/share/nvim/lazy/copilot.lua/copilot/node_modules/@vscode/chat-lib/src/_internal/platform/tokenizer/node/tokenizer.ts:265:28)
    at W1e.tokenize (/home/ilex/.local/share/nvim/lazy/copilot.lua/copilot/node_modules/@vscode/chat-lib/src/_internal/platform/tokenizer/node/tokenizer.ts:130:22)
    at W1e._textTokenLength (/home/ilex/.local/share/nvim/lazy/copilot.lua/copilot/node_modules/@vscode/chat-lib/src/_internal/platform/tokenizer/node/tokenizer.ts:170:29)
    at W1e.tokenLength (/home/ilex/.local/share/nvim/lazy/copilot.lua/copilot/node_modules/@vscode/chat-lib/src/_internal/platform/tokenizer/node/tokenizer.ts:140:16)
    at W1e.countMessageObjectTokens (/home/ilex/.local/share/nvim/lazy/copilot.lua/copilot/node_modules/@vscode/chat-lib/src/_internal/platform/tokenizer/node/tokenizer.ts:212:29): Error on conversation request] 
2025-10-17 15:27:09.145 [213] [ERROR]: LSP message: [lsp] Request textDocument/copilotInlineEdit: Error: An unexpected error occurred: {"type":"failed","reason":"Error on conversation request. Check the log for more details.","requestId":"7fd175bf-8805-45c7-b208-35d53c5d16ab"}
    at Object.fromUnknown (/home/ilex/.local/share/nvim/lazy/copilot.lua/copilot/node_modules/@vscode/chat-lib/src/_internal/util/common/errors.ts:17:9)
    at Function.mapChatFetcherErrorToNoNextEditReason (/home/ilex/.local/share/nvim/lazy/copilot.lua/copilot/node_modules/@vscode/chat-lib/src/_internal/extension/xtab/node/xtabProvider.ts:842:53)
    at Eze.streamEdits (/home/ilex/.local/share/nvim/lazy/copilot.lua/copilot/node_modules/@vscode/chat-lib/src/_internal/extension/xtab/node/xtabProvider.ts:532:39)
    at processTicksAndRejections (node:internal/process/task_queues:105:5)

My configuration for copilot.lsp:

return {
  "zbirenbaum/copilot.lua",
  dependencies = {
    "copilotlsp-nvim/copilot-lsp", -- (optional) for NES functionality
  },
  cmd = "Copilot",
  event = "InsertEnter",
  config = function()
      require("copilot").setup({
          nes = {
              enabled = true, -- requires copilot-lsp as a dependency
              auto_trigger = true,
              keymap = {
                  accept_and_goto = "<M-j>",
                  accept = false,
                  dismiss = "<Esc>",
              },
          },
          suggestion = {
              enabled = true,
              auto_trigger = true,
              hide_during_completion = true,
              debounce = 75,
              trigger_on_accept = true,
              keymap = {
                  accept = "<C-c>",
                  accept_word = "<C-x>",
                  accept_line = "<C-v>",
                  next = "<M-v>",
                  prev = "<M-x>",
                  dismiss = "<C-]>",
              },
          },
    })
  end,
}

I am not sure what causes this error, but the file it is trying to access really does not exist. I assume this might be a misconfiguration somewhere, but I tried to remove and reinstall the plugin, no luck there. Any ideas what I might be doing wrong? And btw thanks for the amazing plugin!

[Jay-Madden]

I am also seeing this same issue with the following config.

      suggestion = {
        auto_trigger = false,
        auto_refresh = true,
        keymap = {
          accept = "<leader>cca",
          next = "<leader>ccn",
          prev = "<leader>ccp",
          dismiss = "<leader>ccd",
        },
      },
      nes = {
        enabled = true,
        keymap = {
          accept_and_goto = "<leader>p",
          accept = false,
          dismiss = "<Esc>",
        },
      },

However, if i install the copilot language server manually npm install @github/copilot-language-server and use this config

      suggestion = {
        auto_trigger = false,
        auto_refresh = true,
        keymap = {
          accept = "<leader>cca",
          next = "<leader>ccn",
          prev = "<leader>ccp",
          dismiss = "<leader>ccd",
        },
      },
      nes = {
        enabled = true,
        keymap = {
          accept_and_goto = "<leader>p",
          accept = false,
          dismiss = "<Esc>",
        },
      },
      server = {
        type = "binary",
        custom_server_filepath = "/opt/homebrew/bin/copilot-language-server",
      },

copilot.nvim nes does work. So i think its some issue with the new cls version that was added a few days ago?

[ammen99]

@Jay-Madden Thank you for the suggestion, I can confirm your workaround works for me as well.