My settings for shell are:
set shell=powershell\ -ExecutionPolicy\ Unrestricted\ -NoProfile\ -NoLogo\ -NonInteractive
set shellcmdflag=-Command
And when i'm using that, I'm getting following error
E97: Cannot create diffs
But when I revert back to default windows shell (cmd) that's working fine.
I tried to set shell in diffexpr function, but got an error on calling diff.exe (I haven't found error message).