> For the complete documentation index, see [llms.txt](https://guide.prismlive.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://guide.prismlive.com/desktop/guides/error-solution/error-information/dual-output-error-solution-guide.md).
# Dual Output – Error Solution Guide
### Overview
PRISM Live Studio provides a **Dual Output** feature that allows you to stream both **horizontal** and **vertical** broadcasts simultaneously.\
This feature lets creators deliver content optimized for both PC and mobile viewers at the same time.
However, some users have encountered the following error message:
This error occurs when Dual Output is enabled, but **only one of the two outputs** — either **Horizontal Output** or **Vertical Output** — has a connected channel.
### Cause
When using the Dual Output feature, you must connect **at least two channels**, and both output directions must have assigned channels.
To summarize:
1. At least **two streaming channels** must be connected.
2. Both **Horizontal Output** and **Vertical Output** must have their respective channels assigned.
***
### Solution
#### CASE 1. Only one channel is linked while Dual Output is enabled
**Problem**
You are trying to use Dual Output, but only **one channel** has been connected.
**Solution**
1. Click the **three-dot menu (⋮)** next to **My Channel**.
2. Select **Add Channels** to connect an additional channel.
* At least two channels must be connected to use Dual Output.
3. After adding the channel, make sure both **Horizontal Output** and **Vertical Output** are properly assigned.
4. Click **Go Live** to begin your broadcast.
***
#### CASE 2. Multiple channels are linked, but only one output is assigned
**Problem**
Dual Output is enabled and more than one channel is connected,\
but only one output (e.g., **Horizontal Output**) has been configured — while the other (**Vertical Output**) remains empty.
**Solution**
1. Hover over a channel and click the **Dual Output icon (PC + Mobile icon)**.
2. Select the unassigned output (e.g., **Vertical Output**) to assign a channel.
3. Verify that both **Horizontal Output** and **Vertical Output** have connected channels.
4. Click **Go Live** to begin your broadcast.
---
# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.
## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.
Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:
```
GET https://guide.prismlive.com/desktop/guides/error-solution/error-information/dual-output-error-solution-guide.md?ask=&goal=
```
`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.
Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.