# A solution to the incredibly unhelpful "the router uses a non-existent resolver: letsencrypt" message

**URL:** <https://community.traefik.io/t/a-solution-to-the-incredibly-unhelpful-the-router-uses-a-non-existent-resolver-letsencrypt-message/3859>\
**Category:** Traefik v2\
**Tags:** letsencrypt-acme\
**Created:** [January 14, 2020, 9:02pm UTC](https://community.traefik.io/t/a-solution-to-the-incredibly-unhelpful-the-router-uses-a-non-existent-resolver-letsencrypt-message/3859 "2020-01-14T21:02:31Z")\
**Posts on this page:** 1\
**Showing post:** 2

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**Author:** ![somebody](https://avatars.discourse-cdn.com/v4/letter/s/3ab097/32.png) [@somebody](https://community.traefik.io/u/somebody)\
**Post date:** [January 14, 2020, 9:04pm UTC](https://community.traefik.io/t/a-solution-to-the-incredibly-unhelpful-the-router-uses-a-non-existent-resolver-letsencrypt-message/3859/2 "2020-01-14T21:04:55Z")

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Replying so i can mark as solution:

**TL;DR:** Traefik 2.x does not indicate when the `acme.json` file could be opened but contains invalid data. In this case, the certificate resolver silently fails resulting in the cryptic "router uses non-existant resolver..." messages. Do not attempt to manage the JSON file outside of traefik; even a simple `touch acme.json` will break things w/o much of a clue in the logs.

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_[View the full topic](https://community.traefik.io/t/a-solution-to-the-incredibly-unhelpful-the-router-uses-a-non-existent-resolver-letsencrypt-message/3859)._