**System Information**
Operating system: Win 10 x64
Graphics card: Nvidia 310m
**Blender Version**
Broken: (example: 2.80, edbf15d3c044, master, 2018-11-28, as found on the splash screen)
Worked: (optional)
**Short description of error**
When deleting a Cycles sampling preset, an exception popuped, and deleting failed.
**Exact steps for others to reproduce the error**
Based on the default startup or an attached .blend file (as simple as possible).
1. "Render Properties" panel, change Render engine to Cycles
2. "Sampling" section, use "+" sign add "New Preset"
3. press "-" sign right to "New Preset". Here prompt "Add a sampling preset." It should be "Delete a sampling preset."
4. Exeption happen, and deleting fail.
{F8299051}
{F8299053}
{F8299055}
{F8299057}