> ## Documentation Index
> Fetch the complete documentation index at: https://docs.ntop.com/llms.txt
> Use this file to discover all available pages before exploring further.

# The info panel shows a "Stream error" message when trying to import a mesh file

## Issue:

**Import Mesh** block displays the message "Stream error" when trying to open an STL file.

## Applies to:

* ASCII STL

## Cause:

This error occurs if an STL was created using an ASCII representation, and the Header exceeds 100 characters.

## Solution:

1. Make a copy of the STL as a backup.
2. Right-click the STL file and select **Open with > Notepad**
3. On the first line, after the word "solid," eliminate some text until the Header contains fewer than 100 characters.
4. Click **File > Save**

## Keywords:

*stl mesh file 2.22 stream stream error import mesh*