**System Information**
Operating system: Windows-10-10.0.19041-SP0 64 Bits
Graphics card: GeForce GTX 1080/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 456.71
**Blender Version**
Broken: version: 3.0.0 Alpha, branch: master (modified), commit date: 2021-06-23 04:56, hash: `rB071799d4fc44`
Worked: (newest version of Blender that worked as expected)
**Short description of error**
Geometry nodes crash when two nodes that are connected to a reroute and feed into "Join Geometry" are both muted.
**Exact steps for others to reproduce the error**
{F10191293}
1. Make a default geometry node tree.
1. Add a "Join Geometry" node.
1. Add two arbitrary input nodes (i used "Assign Material").
1. Connect both input nodes to a "Reroute" node.
1. Feed some source geometry into the Reroute node.
1. **Mute** both nodes feeding into the Join Geometry
1. Geometry nodes assert fails, because the Join Geometry node has not computed any output geometry.
{F10191292}