Plugin works in debug mode but fails to install as .difypkg (Internal Server Error)

Discussion
1

Plugin works in debug mode but fails to install as .difypkg (Internal Server Error)

Dify version: 1.13.3 (self-hosted Docker Compose)
Plugin daemon version: 0.5.4

Description

I’m developing a model provider plugin for OVH AI Endpoints (source: GitHub - rungeard/dify_ovh_ai_endpoints: Dify plugin for OVH AI Endpoints with predefined LLM, Embeddings, Speech-to-Text, and Text-to-Speech models. · GitHub ).

When I run the plugin in remote debug mode (as described in the official docs), everything works perfectly — the plugin connects, models are installed, and no errors are thrown.

However, when I package the plugin into a .difypkg file and try to install it via the Dify UI (local file upload), I consistently get an Internal Server Error.

difypkg file → https://jirafeau.rungeard.eu/f.php?h=2X9KtIFs&d=1

What I’ve tried

  • Set FORCE_VERIFYING_SIGNATURE=false and ENFORCE_LANGGENIUS_PLUGIN_SIGNATURES=false in .env
  • Ensured all files use LF line endings (not CRLF)

What the logs show

The upload succeeds (HTTP 200), but the subsequent decode/from_identifier call returns 400:

plugin_daemon | record not found
SELECT * FROM "plugin_declarations" WHERE plugin_unique_identifier = 'rungeard/ovh_ai_endpoints:0.0.1@...' LIMIT 1

The plugin_declarations table remains empty after every upload attempt. It seems the daemon successfully stores the package file but never registers it in the database, causing the decode step to fail.

Question

Is there a known issue with local .difypkg installation on plugin daemon? Could there be a validation step between upload/package and decode/from_identifier that silently rejects the package without logging a meaningful error?

Any help appreciated!

2

:white_check_mark: Root cause identified – Dify 1.13.3 regression on local plugin installation

I ran into the exact same issue:

  • Plugin works perfectly in remote debug mode

  • .difypkg uploads successfully

  • Installation fails almost instantly with Internal Server Error

  • Logs show:

    /management/decode/from_identifier ... status=400

After investigation, this is NOT a plugin issue (manifest, code, dependencies, etc.).
The failure happens before plugin execution, during the decode phase in the plugin daemon.

:magnifying_glass_tilted_left: Root cause

This is caused by a regression in Dify 1.13.3 affecting local plugin installation.

The failing step is:

decode_plugin_from_identifier → plugin_daemon /decode/from_identifier → 400

Even though plugin_unique_identifier is correctly passed, the daemon rejects it.

:white_check_mark: Solution

Downgrading Dify API fixes the issue immediately:

:backhand_index_pointing_right: Use Dify 1.13.2 instead of 1.13.3

After downgrade:

  • Same .difypkg

  • Same environment

  • Installation works instantly

:link: Related issues

These issues point to the same root cause: