"Message 'at' not understood."

Hello, After installing Unit-Lib, I get this message at Supercollider startup (on Windows 10).
Message 'at' not understood.
Specifically, this is the whole log:
compiling class library...
    Found 833 primitives.
    Compiling directory 'C:\Program Files\SuperCollider-3.10.3\SCClassLibrary'
    Compiling directory 'C:\ProgramData\SuperCollider\Extensions'
    Compiling directory 'C:\Users\xan_9\AppData\Local\SuperCollider\Extensions'
    Compiling directory 'C:\Users\xan_9\AppData\Local\SuperCollider\downloaded-quarks\MathLib'
    Compiling directory 'C:\Users\xan_9\AppData\Local\SuperCollider\downloaded-quarks\NetLib'
    Compiling directory 'C:\Users\xan_9\AppData\Local\SuperCollider\downloaded-quarks\PopUpTreeMenu'
    Compiling directory 'C:\Users\xan_9\AppData\Local\SuperCollider\downloaded-quarks\VectorSpace'
    Compiling directory 'C:\Users\xan_9\AppData\Local\SuperCollider\downloaded-quarks\XML'
    Compiling directory 'C:\Users\xan_9\AppData\Local\SuperCollider\downloaded-quarks\wslib'
    numentries = 1753345 / 37341792 = 0.047
    8874 method selectors, 4208 classes
    method table size 34832104 bytes, big table size 298734336
    Number of Symbols 21517
    Byte Code Size 894109
    compiled 961 files in 1.13 seconds

Info: 5 methods are currently overwritten by extensions. To see which, execute:
MethodOverride.printAll

compile done
localhost : setting clientID to 0.
internal : setting clientID to 0.
ERROR: Message 'at' not understood.
RECEIVER:
   nil
ARGS:
   Symbol 'global'
CALL STACK:
    DoesNotUnderstandError:reportError
        arg this = <instance of DoesNotUnderstandError>
    Nil:handleError
        arg this = nil
        arg error = <instance of DoesNotUnderstandError>
    Thread:handleError
        arg this = <instance of Thread>
        arg error = <instance of DoesNotUnderstandError>
    Object:throw
        arg this = <instance of DoesNotUnderstandError>
    Object:doesNotUnderstand
        arg this = nil
        arg selector = 'at'
        arg args = [*1]
    Meta_SynthDescLib:getLib
        arg this = <instance of Meta_SynthDescLib>
        arg libname = 'global'
    SynthDef:asSynthDesc
        arg this = <instance of SynthDef>
        arg libname = 'global'
        arg keepDef = true
        var lib = nil
        var stream = <instance of CollStream>
    SynthDef:writeDefFile
        arg this = <instance of SynthDef>
        arg dir = "C:\Users\xan_9\AppData\Local..."
        arg overwrite = false
        arg mdPlugin = nil
        var desc = nil
        var defFileExistedBefore = false
    SynthDef:writeOnce
        arg this = <instance of SynthDef>
        arg dir = nil
        arg mdPlugin = nil
    Meta_UDragSource:initClass
        arg this = <instance of Meta_UDragSource>
    Meta_Class:initClassTree
        arg this = <instance of Meta_Class>
        arg aClass = <instance of Meta_UDragSource>
        var implementsInitClass = nil
    ArrayedCollection:do
        arg this = [*449]
        arg function = <instance of Function>
        var i = 239
    Meta_Class:initClassTree
        arg this = <instance of Meta_Class>
        arg aClass = <instance of Meta_Object>
        var implementsInitClass = nil
    Process:startup
        arg this = <instance of Main>
        var time = 1.1633914
    Main:startup
        arg this = <instance of Main>
        var didWarnOverwrite = false
^^ The preceding error dump is for ERROR: Message 'at' not understood.
RECEIVER: nil

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GameOfLife / Unit-Lib

"Message 'at' not understood." #58
