Unexpected use of an aliased name after git pull to Windows

Currently, I have problems using the GameLiftSDK with Unity 2021.3.16f. My colleague set everything properly up on his Macbook. To do so, he used the Plugin.

After pushing it to git and pulling it to my windows 10 machine I get the following Error Messages: "

1. Assets\Scripts\AWSGamelift\GameLiftClient.cs(14,31): error CS7000: Unexpected use of an aliased name" and
2. Failed to find entry-points:" Mono.Cecil.AssemblyResolutionException: Failed to resolve assembly: 'Assembly-CSharp, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null' at Mono.Cecil.BaseAssemblyResolver.Resolve (Mono.Cecil.AssemblyNameReference name, Mono.Cecil.ReaderParameters parameters) [0x00105] in <ebb9e4250ed24cbfa42055e3532ef311>:0 at zzzUnity.Burst.CodeGen.AssemblyResolver.Resolve (Mono.Cecil.AssemblyNameReference name) [0x00039] in <a2dd15248a25411e914af2a2c82fb63f>:0 at Burst.Compiler.IL.AssemblyLoader.Resolve (Mono.Cecil.AssemblyNameReference name) [0x00079] in <a2dd15248a25411e914af2a2c82fb63f>:0 at Burst.Compiler.IL.Server.EntryPointMethodFinder.FindEntryPoints (System.String[] rootAssemblyNames, Burst.Compiler.IL.Hashing.CacheRuntime.HashCacheAssemblyStore assemblyStore, Burst.Compiler.IL.AssemblyLoader assemblyLoader, Burst.Compiler.IL.NativeCompilerOptions options, Burst.Compiler.IL.Server.ProfileDelegate profileCallback, System.Boolean includeRootAssemblyReferences, System.Boolean splitTargets, Burst.Compiler.IL.Helpers.DebugLogWriter debugWriter) [0x00055] in <a2dd15248a25411e914af2a2c82fb63f>:0 at Burst.Compiler.IL.Server.FindMethodsJob.Execute (Burst.Compiler.IL.Server.CompilerServerJobExecutionContext context) [0x00133] in <a2dd15248a25411e914af2a2c82fb63f>:0

While compiling job:"

All dlls seem to be there.

Hope you can help me and thanks already for your time.