Arduino IDE: Error while setting serial port parameters: 115,200 N 8 1 (Freezes while opening Serial Monitor or Plotter)

[glydrfreak]

Verbose output during sketch upload:

...
[==============================] 100% (1183/1183 pages)
done in 0.458 seconds

Verify 75712 bytes of flash with checksum.
checksumBuffer(start_addr=0x2000, size=0x1000) = 36f5
checksumBuffer(start_addr=0x3000, size=0x1000) = 6a4b
checksumBuffer(start_addr=0x4000, size=0x1000) = 74d3
checksumBuffer(start_addr=0x5000, size=0x1000) = de39
checksumBuffer(start_addr=0x6000, size=0x1000) = 6246
checksumBuffer(start_addr=0x7000, size=0x1000) = 4cff
checksumBuffer(start_addr=0x8000, size=0x1000) = 2116
checksumBuffer(start_addr=0x9000, size=0x1000) = 61eb
checksumBuffer(start_addr=0xa000, size=0x1000) = beb9
checksumBuffer(start_addr=0xb000, size=0x1000) = a7a6
checksumBuffer(start_addr=0xc000, size=0x1000) = b8d8
checksumBuffer(start_addr=0xd000, size=0x1000) = 6e5d
checksumBuffer(start_addr=0xe000, size=0x1000) = 2ce8
checksumBuffer(start_addr=0xf000, size=0x1000) = 891f
checksumBuffer(start_addr=0x10000, size=0x1000) = f04c
checksumBuffer(start_addr=0x11000, size=0x1000) = b26c
checksumBuffer(start_addr=0x12000, size=0x1000) = cd51
checksumBuffer(start_addr=0x13000, size=0x1000) = c829
checksumBuffer(start_addr=0x14000, size=0x7c0) = c81d
Verify successful
done in 0.054 seconds
CPU reset.
readWord(addr=0)=0x20007ffc
readWord(addr=0xe000ed00)=0x410cc601
readWord(addr=0x41002018)=0x10010305
writeWord(addr=0xe000ed0c,value=0x5fa0004)

Error while setting serial port parameters: 115,200 N 8 1

[glydrfreak]

POTENTIALLY USEFUL CLUES:

• Visual Studio occasionally enters a (not responding) state during a sketch upload.
  As soon as I unplug the Feather M0, Visual Studio immediately responds again.

• Similarly with Arduino IDE, trying to open up a Serial Monitor or Plotter freezes the IDE.
  As soon as I unplug the Feather M0, a blank Serial Monitor/Plotter immediately appears.