Doing Add on repository root fails with libgit2 returned invalid path"

I'm using a Windows 7 x64 PC and I just updated to Tortoise GIT release 2.4.0.0 (64 bit) - now every time I try to do an "add" to a repository I get this:

libgit2 returned: invalid path: "
Finished!  Fail (15 ms @ [current date and time]

The operation failed.

DebugView gives this output:

[9240] CGit::CheckMsysGitDir: CheckMsysGitDir(1)
[9240] CGit::CheckMsysGitDir: ms_LastMsysGitDir = C:\Program Files\Git\bin
[9240] CGit::CheckMsysGitDir: ms_MsysGitRootDir = C:\Program Files\Git\mingw64\
[9240] CGit::CheckMsysGitDir: System config = C:\Program Files\Git\mingw64\etc\gitconfig
[9240] CGit::CheckMsysGitDir: ProgramData config = C:\ProgramData\Git\config
[9240] CTortoiseProcApp::CTortoiseProcApp: Constructor
[9240] CTortoiseProcApp::InitInstance: InitInstance
[9240] CTortoiseProcApp::CheckUpgrade: Current TGit Version 2.4.0.0
[9240] CTortoiseProcApp::InitInstance: Set Help Filename C:\Program Files\TortoiseGit\bin\TortoiseGit_en.chm
[9240] CTortoiseProcApp::InitInstance: Initializing UI components ...
[9240] CGit::CheckMsysGitDir: CheckMsysGitDir(1)
[9240] CGit::CheckMsysGitDir: ms_LastMsysGitDir = C:\Program Files\Git\bin
[9240] CGit::CheckMsysGitDir: ms_MsysGitRootDir = C:\Program Files\Git\mingw64\
[9240] CGit::CheckMsysGitDir: System config = C:\Program Files\Git\mingw64\etc\gitconfig
[9240] CGit::CheckMsysGitDir: ProgramData config = C:\ProgramData\Git\config
[9240] CTortoiseProcApp::InitInstance: Registering Crash Report ...

Previously, I was using release 2.3.0.0 (64 bit) without issues.

Michael Tracy