CSP-Power Tower - crashes with single facet heliostat

[kjkattke]

Describe the bug

SAM GUI crashes when updating default Power tower model to a single facet heliostat.

To Reproduce

Steps to reproduce the behavior:

1. Open default CSP -> Power tower model
2. In Heliostat Field tab, change 'Number of heliostat facets - X' to 1
3. In Heliostat Field tab, change 'Number of heliostat facets - y' to 1
   • causes GUI to crash

Note: tried setting 'Heliostat canting method' to None before step 2 above and still caused crash after step 3.

Expected behavior

Screenshots

Operating System and Version

• OS: Windows
• Version SAM 2025.4.16

Additional context

Issue does not occur in SAM V2021.12.2, but found to occur on all versions I have installed after this.