Game and Plater version
Which is the game version and Plater version you're using?
Plater version info:
Plater-v569-Retail - DF v482 - 10.2.0

• When the bug started (a date, wow path release, details update, etc)?
  Today

Lua Error
6x Plater/Plater.lua:817: IsSpellInRange(): Invalid spell slot
[string "=[C]"]: in function IsSpellInRange' [string "@Plater/Plater.lua"]:817: in function rangeChecker'
[string "@Plater/Plater.lua"]:852: in function CheckRange' [string "@Plater/Plater.lua"]:6626: in function UpdateTarget'
[string "@Plater/Plater.lua"]:7747: in function UpdatePlateFrame' [string "@Plater/Plater.lua"]:3597: in function func'
[string "@Plater/Plater.lua"]:3850: in function <Plater/Plater.lua:3846>

Locals:
(*temporary) = nil
(*temporary) = "nameplate1"

Should be fixed in the latest alpha. Related to #185