Critical data loss after consecutive updates (sessions, history, plugins and providers disappeared)

Description

Hello.

After installing several consecutive updates (around 3 updates within a few hours), OpenCode became unusable.

The issues I encountered are:

All of my existing sessions can no longer be opened.
My entire chat history is gone, including a long-term project that represented weeks of work.

Existing tabs now display:

"This session cannot be found."

The Plugins section disappeared completely.
My MCP list became empty.
No providers are available anymore, so I cannot select any model.
Even the model search returns nothing.
The only remaining option is adding a custom provider manually.

The browser console also shows multiple errors such as:

Cannot read properties of undefined (reading 'temperature')
UnsupportedContentType
HTTP 400 Bad Request

Downgrading from v1.18.9 back to v1.18.0 restores the Providers, MCPs and Plugins, which strongly suggests a regression introduced in recent releases.

Unfortunately, my session history/database appears to have been lost during the update.

Please avoid updates that can silently destroy user data, or at least warn users before performing any database or storage migration.

Thank you.

Plugins

opencode-mem , lm-studio

OpenCode version

1.18.9

Steps to reproduce

No response

Screenshot and/or share link

Operating System

windows 11, Ubuntu 26.0.4, Debian 13.5

Terminal

PowerShell, Bash