Why I can not generate a new project in ubuntu?

when I tried: GenerateProjectFiles.sh b.uproject -game -engine gave me this error: Attempting to set up UE4 pretty printers for gdb (existing UE4Printers.py, if any, will be overwritten)…
updated UE4Printers.py
found necessary entries in ~/.gdbinit file, not changing it.

Setting up Unreal Engine 4 project files…

Fixing inconsistent case in filenames.
Setting up Mono
ERROR: Unhandled exception: System.IO.FileNotFoundException: Could not find file “/home//UnrealEngine/Engine/Source/b.uproject”
File name: ‘/home//UnrealEngine/Engine/Source/b.uproject’
at System.IO.FileStream…ctor (System.String path, System.IO.FileMode mode, System.IO.FileAccess access, System.IO.FileShare share, System.Int32 bufferSize, System.Boolean anonymous, System.IO.FileOptions options) [0x0019e] in <98fac219bd4e453693d76fda7bd96ab0>:0
at System.IO.FileStream…ctor (System.String path, System.IO.FileMode mode, System.IO.FileAccess access, System.IO.FileShare share, System.Int32 bufferSize, System.IO.FileOptions options, System.String msgPath, System.Boolean bFromProxy, System.Boolean useLongPath, System.Boolean checkHost) [0x00000] in <98fac219bd4e453693d76fda7bd96ab0>:0
at (wrapper remoting-invoke-with-check) System.IO.FileStream…ctor(string,System.IO.FileMode,System.IO.FileAccess,System.IO.FileShare,int,System.IO.FileOptions,string,bool,bool,bool)
at System.IO.StreamReader…ctor (System.String path, System.Text.Encoding encoding, System.Boolean detectEncodingFromByteOrderMarks, System.Int32 bufferSize, System.Boolean checkHost) [0x00067] in <98fac219bd4e453693d76fda7bd96ab0>:0
at System.IO.StreamReader…ctor (System.String path, System.Text.Encoding encoding, System.Boolean detectEncodingFromByteOrderMarks, System.Int32 bufferSize) [0x00000] in <98fac219bd4e453693d76fda7bd96ab0>:0
at System.IO.StreamReader…ctor (System.String path, System.Boolean detectEncodingFromByteOrderMarks) [0x0000d] in <98fac219bd4e453693d76fda7bd96ab0>:0
at System.IO.StreamReader…ctor (System.String path) [0x00000] in <98fac219bd4e453693d76fda7bd96ab0>:0
at (wrapper remoting-invoke-with-check) System.IO.StreamReader…ctor(string)
at System.IO.File.ReadAllText (System.String path) [0x00000] in <98fac219bd4e453693d76fda7bd96ab0>:0
at Tools.DotNETCommon.FileReference.ReadAllText (Tools.DotNETCommon.FileReference Location) [0x00000] in :0
at Tools.DotNETCommon.JsonObject.Read (Tools.DotNETCommon.FileReference File) [0x00000] in :0
at UnrealBuildTool.ProjectDescriptor.FromFile (Tools.DotNETCommon.FileReference FileName) [0x00000] in :0
at UnrealBuildTool.ProjectFileGenerator.ConfigureProjectFileGeneration (System.String[] Arguments, System.Boolean& IncludeAllPlatforms) [0x003f9] in :0
at UnrealBuildTool.ProjectFileGenerator.GenerateProjectFiles (UnrealBuildTool.PlatformProjectGeneratorCollection PlatformProjectGenerators, System.String[] Arguments) [0x0000a] in :0
at UnrealBuildTool.GenerateProjectFilesMode.Execute (Tools.DotNETCommon.CommandLineArguments Arguments) [0x002f0] in :0
at UnrealBuildTool.UnrealBuildTool.Main (System.String[] ArgumentsArray) [0x00291] in :0