"text content is empty" error ruining session using Fusion 360 MCP server

[jakecrowley]

Description

Using Kimi K2.6 with the Kimi For Coding model, when it tries to take a screenshot of the model, it fails with "text content is empty" and causes all subsequent prompts to error with the same thing.

Plugins

none

OpenCode version

1.14.30

Steps to reproduce

1. Add Fusion MCP server
2. Prompt it something that would make it take a screenshot using the fusion_mcp_read tool.
3. "text content is empty"

Screenshot and/or share link

Operating System

Windows 11

Terminal

Windows Terminal

[github-actions]

This issue might be a duplicate of existing issues. Please check:

• text content blocks must be non-empty when using Claude models and tools #24087: Same error ("text content blocks must be non-empty") occurring with Claude models during tool usage, session becomes unusable after the error
• bug: message pipeline has no final empty-content guard, causing ValidationException on Bedrock and hard failures on other providers #23260: Bug describing missing empty-content guard in the message pipeline causing ValidationException
• ValidationException: text content blocks must be non-empty when using Bedrock Runtime #15715: Same ValidationException with text content blocks must be non-empty on Bedrock Runtime

The root cause may be the same — an empty text content block being generated in the message history, possibly when an MCP tool returns non-text (e.g. image/binary) content.

[rekram1-node]

@jakecrowley send me session:

opencode export > session.json