Some users reported that Canon tethering might fail in this version. A common workaround suggested by the Lightroom Queen community is to ensure the Nikon Tethering plugin is actually enabled in the Plug-in Manager, which oddly fixes the Canon connection for some. 10.3 Performance - Adobe Community
As part of the broader 2021 release cycle, v10.4.0 benefits from the hallmark features introduced earlier that year:
The introduction of "Box Zoom" and "Scrubby Zoom" (holding Shift and dragging) made it easier to navigate high-resolution images quickly. System Requirements for 2021 v10.4.0 Adobe Photoshop Lightroom Classic 2021 v10.4.0
The 10.4.0 update focused on stability and expanding hardware support, though it included several quality-of-life improvements for Power users:
If you are still using an older version of Lightroom Classic, you can update to v10.4.0 via the Adobe Creative Cloud desktop app. Some users reported that Canon tethering might fail
To run this version smoothly, your system should meet or exceed these specifications: Minimum Requirement Recommended Intel/AMD with 64-bit & SSE 4.2 (2GHz+) Intel 10th Gen Core i7 or better RAM 16 GB or 32 GB GPU 2 GB VRAM (DirectX 12 / Metal) 4 GB VRAM for 4K displays OS Windows 10 (64-bit) / macOS Catalina Windows 11 / macOS Big Sur Updating and Troubleshooting
Improved use of the graphics processor significantly speeded up brushing, gradients, and overall image rendering in the Develop module. System Requirements for 2021 v10
Following reports of sluggishness in version 10.3 (particularly with the healing brush and zooming), 10.4 targeted these bottleneck areas for a smoother editing experience. Significant Tools from the 2021 (v10.x) Era