Running "Symbol > Selection to Symbol Master" causes Sketch to crash
**Hardware Specs:**
MacBook Pro (Retina, 15-inch, Mid 2014)

**Software Specs:**
macOS Mojave 10.14.6 (18G5033)
Sketch 58.0
Automate Sketch 65.1.2020513

**Steps to Reproduce:**
1. Open a new Sketch document
2. Create a new Artboard
3. Run `Plugins > Automate > Symbol > Selection to Symbol Master`

**Expected Behavior:**
Selected artboard is converted to a symbol.

**Observed Behavior:**
Sketch crashes

**What I've tried:**
- [x] Re-installing Sketch
- [x] Re-installing the Automate Sketch plugin
- [x] Downgrading Automate Sketch to a matching version (58.0.20191010)

Even with the above steps, I am still able to reproduce the issue 100% of the time