LightBurn 2.1.03 Update Issues: What Makers Are Reporting

The latest LightBurn update, version 2.1.03, has brought a wave of user reports across the community. While updates often introduce new features, they can also introduce unexpected bugs. This roundup summarizes the most common issues reported by makers, from speed control problems to connection failures and cutting quality degradation. We’ll break down what’s happening, why it matters, and practical steps you can take if you’re affected.

Speed Control and Preset Issues After LightBurn 2.1.03

Source: Laser Speed Control · Published August 3, 2026.

A Sculpfun 9S user reported that after updating to LightBurn 2.1.03, all their preset cut settings changed to 63.33 speed and 60 power, and they lost control over the laser speed. The laser only runs at a fixed speed, ignoring the settings. This issue appeared after a few weeks away from the workshop, suggesting the update may have reset or corrupted settings.

Why it matters for laser makers

For makers who rely on precise speed and power settings for different materials, a sudden reset can ruin projects and waste material. If you’ve updated and notice your presets are off or speed control is unresponsive, check your settings and consider reverting to a previous version if the problem persists. This issue highlights the importance of backing up your LightBurn settings before updating.

Connection Problems with Sculpfun S9 and LightBurn Trial

Source: Lightburn not connect with my laser · Published August 2, 2026.

A user with a Sculpfun S9 could not get LightBurn (trial version) to connect reliably. They could occasionally get it to frame, but the laser wouldn’t fire or perform a test image. LaserGRBL connected fine and worked, but LightBurn showed ‘Waiting for…’ messages. The user had to repeatedly turn the machine on/off and restart the app to get any response.

Why it matters for laser makers

Connection issues are frustrating and can halt production. If you’re using a trial version or just updated, ensure you have the correct driver and port settings. Sometimes, other software like LaserGRBL can conflict with LightBurn’s connection. Try closing other programs, using a different USB port, or reinstalling the driver. This report underscores the need for robust connection troubleshooting when switching software.

Laser Not Cutting After LightBurn Update: Sculpfun S30 Pro

Source: Laser not cutting after Lightburn update · Published August 1, 2026.

A Sculpfun S30 Pro user reported that after updating to LightBurn 2.1.03, their laser no longer cuts through material—it only makes lines on wood. They cleaned and swapped the lens, but the issue persisted. The laser cut fine the day before the update, pointing to a software-related problem.

Why it matters for laser makers

This is a critical issue for anyone who relies on their laser for cutting. If your laser is only engraving after an update, it could be due to changed settings, firmware communication, or a bug in the update. Before assuming hardware failure, check your power and speed settings, and consider rolling back to a previous LightBurn version. This report emphasizes the importance of testing after updates and keeping backups of known-good settings.

Partial Uploads to Ruida Controllers After LightBurn Update

Source: Partial upload to Ruida · Published July 31, 2026.

A user with a 100W CO2 laser and Ruida controller reported that after updating to the latest LightBurn, sending text to engrave only uploads about 1/4 of the data, then errors with ‘There was a problem sending data to the laser. The machine may be busy or paused.’ Simple line cuts work fine, but complex text jobs fail. The issue started after the upgrade, and the user suspects a buffer overload.

Why it matters for laser makers

For CO2 laser owners, this is a serious workflow disruption. If you’re experiencing partial uploads, it could be due to increased data size or a communication bug. Try reducing the complexity of the job, increasing the buffer size in LightBurn settings, or using a wired connection if possible. This report highlights the importance of monitoring data transfer when updating software, especially for larger engraving tasks.

What to watch next

The reports around LightBurn 2.1.03 suggest that while the update brings new features, it has also introduced several bugs affecting different machines. If you’re experiencing issues, the first step is to check the LightBurn forum for official responses and workarounds. Always back up your settings and test with a small job after any update. The community is actively discussing these issues, so stay tuned for potential fixes in future releases.