Here are some compilation of errors i encountered and here are the solutions

Some errors I got and how I fixed it: (ERROR 1):

  [flutter] flutter doctor -v 'crumb' is not recognized as an internal or external command, operable program or batch file. 
            Error: Unable to find git in your PATH. exit code 1

(Fix) - Go to flutter installation folder and inside flutter/bin edit the flutter.bat file using a text editor and remove the line (20) that says:

IF EXIST "%mingit_path%" SET PATH=%PATH%;%mingit_path%

The code should look like this on those lines:

REM If available, add location of bundled mingit to PATH 
SET mingit_path=%FLUTTER_ROOT%\bin\mingit\cmd

Save and Run flutter doctor and everything should work fine.

(ERROR 2):

flutter doctor takes too long

(Fix) - I downloaded the previous version of the sdk it worked like a charm.

(ERROR 3):

 Android sdkmanager not found. Update to the latest Android SDK and ensure that the cmdline-tools are installed to resolve this. 

(Fix):

• Open Android Studio
• Tools Menu, SDK Manager
• In the window that comes up there are inner panels, choose SDK Tools panel
• Tick Android SDK Command-line Tools
• Choose Apply button near the bottom of the window

This worked.

(ERROR 4):

  The term 'flutter' is not recognized as the name of a cmdlet, function, script file, or operable program.

(Fix) - Put the correct part in the env variables. I had put D:\flutter instead of D:\flutter\bin. That worked.