[bug]: R2/B2 project cover upload 501 Not Implemented

[PatelGtech]

Is there an existing issue for this?

• I have searched the existing issues

Current behavior

I am using 1.2.3 self hosted version. I am using external S3, I used Cloudflare R2 and BackBlaze B2, When I am trying to create a project, I see the endpoint to upload image to S3 storage is failing.

ENV:
AWS_REGION: auto
AWS_ACCESS_KEY_ID: <access_key>
AWS_SECRET_ACCESS_KEY: <secret_key>
AWS_S3_ENDPOINT_URL: https://<account_id>.eu.r2.cloudflarestorage.com
AWS_S3_BUCKET_NAME: <bucket_name>
FILE_SIZE_LIMIT: 5242880

I do not know why this 501 not implemented error is coming and how do I fix it.

Steps to reproduce

Login
Create Project
Enter Project Name
Click Create
See Networks Tab
Error observed

Environment

Production

Browser

Google Chrome

Variant

Self-hosted

Version

1.2.3

[makeplane]

Synced with Plane Workspace 🔄

[GIT-142] [bug]: R2/B2 project cover upload 501 Not Implemented

[pranjalsh99]

Hey @PatelGtech, Plane uses generate_presigned_post for all file uploads (covers, avatars, attachments, etc.), which generates a POST-based presigned URL. Cloudflare R2 doesn't support this — it only supports PUT-based presigned URLs, which is what's causing the 501 Not Implemented error. For now, we'd recommend using MinIO or AWS S3 as your storage backend instead.