# Fatal error on Kibana startup - 8.19.5 - Windows Server 2025 - Error: Cannot find module '../series\_functions/undefined'

**URL:** <https://discuss.elastic.co/t/fatal-error-on-kibana-startup-8-19-5-windows-server-2025-error-cannot-find-module-series-functions-undefined/382920>\
**Category:** Kibana\
**Created:** [October 23, 2025, 1:20pm UTC](https://discuss.elastic.co/t/fatal-error-on-kibana-startup-8-19-5-windows-server-2025-error-cannot-find-module-series-functions-undefined/382920 "2025-10-23T13:20:43Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![markus](https://avatars.discourse-cdn.com/v4/letter/m/b782af/32.png) [@markus](https://discuss.elastic.co/u/markus)\
**Post date:** [October 23, 2025, 1:20pm UTC](https://discuss.elastic.co/t/fatal-error-on-kibana-startup-8-19-5-windows-server-2025-error-cannot-find-module-series-functions-undefined/382920/1 "2025-10-23T13:20:43Z")

</div>

I’m currently trying to upgrade my ELK Stack from 8.17.8 to 8.19.5.  
OS is Windows Server 2025

When starting Kibana it fails with the following error log:

```auto
[2025-10-23T15:19:48.349+02:00][FATAL][root] Reason: Cannot find module '../series_functions/undefined'
Require stack:

D:\progs\kibana\kibana-8.19.5\node_modules@kbn\vis-type-timelion-plugin\server\lib\load_functions.js

D:\progs\kibana\kibana-8.19.5\node_modules@kbn\vis-type-timelion-plugin\server\plugin.js

D:\progs\kibana\kibana-8.19.5\node_modules@kbn\vis-type-timelion-plugin\server\index.js

D:\progs\kibana\kibana-8.19.5\node_modules@kbn\core-plugins-server-internal\src\plugin.js

D:\progs\kibana\kibana-8.19.5\node_modules@kbn\core-plugins-server-internal\src\discovery\plugins_discovery.js

D:\progs\kibana\kibana-8.19.5\node_modules@kbn\core-plugins-server-internal\src\discovery\index.js

D:\progs\kibana\kibana-8.19.5\node_modules@kbn\core-plugins-server-internal\src\plugins_service.js

D:\progs\kibana\kibana-8.19.5\node_modules@kbn\core-plugins-server-internal\src\index.js

D:\progs\kibana\kibana-8.19.5\node_modules@kbn\core-plugins-server-internal\index.js

D:\progs\kibana\kibana-8.19.5\node_modules@kbn\core-root-server-internal\src\server.js

D:\progs\kibana\kibana-8.19.5\node_modules@kbn\core-root-server-internal\src\index.js

D:\progs\kibana\kibana-8.19.5\node_modules@kbn\core-root-server-internal\index.js

D:\progs\kibana\kibana-8.19.5\node_modules@kbn\core\server\index.js

D:\progs\kibana\kibana-8.19.5\src\cli\serve\serve.js

D:\progs\kibana\kibana-8.19.5\src\cli\cli.js

D:\progs\kibana\kibana-8.19.5\src\cli\dist.js
Error: Cannot find module '../series_functions/undefined'
Require stack:

D:\progs\kibana\kibana-8.19.5\node_modules@kbn\vis-type-timelion-plugin\server\lib\load_functions.js

D:\progs\kibana\kibana-8.19.5\node_modules@kbn\vis-type-timelion-plugin\server\plugin.js

D:\progs\kibana\kibana-8.19.5\node_modules@kbn\vis-type-timelion-plugin\server\index.js

D:\progs\kibana\kibana-8.19.5\node_modules@kbn\core-plugins-server-internal\src\plugin.js

D:\progs\kibana\kibana-8.19.5\node_modules@kbn\core-plugins-server-internal\src\discovery\plugins_discovery.js

D:\progs\kibana\kibana-8.19.5\node_modules@kbn\core-plugins-server-internal\src\discovery\index.js

D:\progs\kibana\kibana-8.19.5\node_modules@kbn\core-plugins-server-internal\src\plugins_service.js

D:\progs\kibana\kibana-8.19.5\node_modules@kbn\core-plugins-server-internal\src\index.js

D:\progs\kibana\kibana-8.19.5\node_modules@kbn\core-plugins-server-internal\index.js

D:\progs\kibana\kibana-8.19.5\node_modules@kbn\core-root-server-internal\src\server.js

D:\progs\kibana\kibana-8.19.5\node_modules@kbn\core-root-server-internal\src\index.js

D:\progs\kibana\kibana-8.19.5\node_modules@kbn\core-root-server-internal\index.js

D:\progs\kibana\kibana-8.19.5\node_modules@kbn\core\server\index.js

D:\progs\kibana\kibana-8.19.5\src\cli\serve\serve.js

D:\progs\kibana\kibana-8.19.5\src\cli\cli.js

D:\progs\kibana\kibana-8.19.5\src\cli\dist.js
at Function._resolveFilename (node:internal/modules/cjs/loader:1401:15)
at defaultResolveImpl (node:internal/modules/cjs/loader:1057:19)
at resolveForCJSWithHooks (node:internal/modules/cjs/loader:1062:22)
at Function._load (node:internal/modules/cjs/loader:1211:37)
at TracingChannel.traceSync (node:diagnostics_channel:322:14)
at wrapModuleLoad (node:internal/modules/cjs/loader:235:24)
at Module. (node:internal/modules/cjs/loader:1487:12)
at Module.patchedRequire (D:\progs\kibana\kibana-8.19.5\node_modules\require-in-the-middle\index.js:194:34)
at Module.Hook._require.Module.require (D:\progs\kibana\kibana-8.19.5\node_modules\require-in-the-middle\index.js:142:27)
at Module.patchedRequire (D:\progs\kibana\kibana-8.19.5\node_modules\require-in-the-middle\index.js:194:34)
at Module.Hook._require.Module.require (D:\progs\kibana\kibana-8.19.5\node_modules\require-in-the-middle\index.js:142:27)
at require (node:internal/modules/helpers:135:16)
at getTuple (D:\progs\kibana\kibana-8.19.5\node_modules@kbn\vis-type-timelion-plugin\server\lib\load_functions.js:22:19)
at D:\progs\kibana\kibana-8.19.5\node_modules@kbn\vis-type-timelion-plugin\server\lib\load_functions.js:39:12
at arrayMap (D:\progs\kibana\kibana-8.19.5\node_modules\lodash\lodash.js:653:23)
at Function.map (D:\progs\kibana\kibana-8.19.5\node_modules\lodash\lodash.js:9622:14)
at interceptor (D:\progs\kibana\kibana-8.19.5\node_modules\lodash\lodash.js:17094:35)
at thru (D:\progs\kibana\kibana-8.19.5\node_modules\lodash\lodash.js:8859:14)
at D:\progs\kibana\kibana-8.19.5\node_modules\lodash\lodash.js:4430:28
at arrayReduce (D:\progs\kibana\kibana-8.19.5\node_modules\lodash\lodash.js:697:21)
at baseWrapperValue (D:\progs\kibana\kibana-8.19.5\node_modules\lodash\lodash.js:4429:14)
at LazyWrapper.lazyValue [as value] (D:\progs\kibana\kibana-8.19.5\node_modules\lodash\lodash.js:1901:16)
at baseWrapperValue (D:\progs\kibana\kibana-8.19.5\node_modules\lodash\lodash.js:4427:25)
at LodashWrapper.wrapperValue (D:\progs\kibana\kibana-8.19.5\node_modules\lodash\lodash.js:9114:14)
at _default (D:\progs\kibana\kibana-8.19.5\node_modules@kbn\vis-type-timelion-plugin\server\lib\load_functions.js:40:6)
at TimelionPlugin.setup (D:\progs\kibana\kibana-8.19.5\node_modules@kbn\vis-type-timelion-plugin\server\plugin.js:33:51)
at PluginWrapper.setup (D:\progs\kibana\kibana-8.19.5\node_modules@kbn\core-plugins-server-internal\src\plugin.js:86:26)
at PluginsSystem.setupPlugins (D:\progs\kibana\kibana-8.19.5\node_modules@kbn\core-plugins-server-internal\src\plugins_system.js:103:40)
at PluginsService.setup (D:\progs\kibana\kibana-8.19.5\node_modules@kbn\core-plugins-server-internal\src\plugins_service.js:120:19)
at Server.setup (D:\progs\kibana\kibana-8.19.5\node_modules@kbn\core-root-server-internal\src\server.js:383:26)
at Root.setup (D:\progs\kibana\kibana-8.19.5\node_modules@kbn\core-root-server-internal\src\root\index.js:58:14)
at bootstrap (D:\progs\kibana\kibana-8.19.5\node_modules@kbn\core-root-server-internal\src\bootstrap.js:118:5)
at Command. (D:\progs\kibana\kibana-8.19.5\src\cli\serve\serve.js:236:5)
[2025-10-23T15:19:48.360+02:00][INFO][plugins-system.preboot] Stopping all plugins.
[2025-10-23T15:19:48.364+02:00][INFO][plugins-system.preboot] All plugins stopped.
[2025-10-23T15:19:48.365+02:00][INFO][plugins-system.standard] Stopping all plugins.
[2025-10-23T15:19:48.375+02:00][INFO][plugins-system.standard] All plugins stopped.

```

When using 8.19.4 i get the same error…

---

<div class="post-metadata">

**Author:** ![Rios](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/rios/32/95745_2.png) [@Rios](https://discuss.elastic.co/u/Rios)\
**Post date:** [October 23, 2025, 1:59pm UTC](https://discuss.elastic.co/t/fatal-error-on-kibana-startup-8-19-5-windows-server-2025-error-cannot-find-module-series-functions-undefined/382920/2 "2025-10-23T13:59:22Z")

</div>

An issue has already been mentioned [here](https://discuss.elastic.co/t/kibana-9-1-4-on-windows-fails-to-start-due-to-timelion-plugin-cannot-find-module-series-functions-undefined/382144)

---

<div class="post-metadata">

**Author:** ![markus](https://avatars.discourse-cdn.com/v4/letter/m/b782af/32.png) [@markus](https://discuss.elastic.co/u/markus)\
**Post date:** [October 23, 2025, 2:34pm UTC](https://discuss.elastic.co/t/fatal-error-on-kibana-startup-8-19-5-windows-server-2025-error-cannot-find-module-series-functions-undefined/382920/3 "2025-10-23T14:34:32Z")

</div>

thx i didn’t realise at first that this was the same problem.

At least for me the suggested fix worked.

I added the following to my kibana.yml

`vis_type_timelion.enabled: false`

Thx for pointing it out!

---

<div class="post-metadata">

**Author:** ![Rios](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/rios/32/95745_2.png) [@Rios](https://discuss.elastic.co/u/Rios)\
**Post date:** [October 23, 2025, 2:36pm UTC](https://discuss.elastic.co/t/fatal-error-on-kibana-startup-8-19-5-windows-server-2025-error-cannot-find-module-series-functions-undefined/382920/4 "2025-10-23T14:36:16Z")

</div>

Excellent. It's a workaround until they solve it.