Troubleshooting - 02 - Uninitialized Constant

Error Message: 

Uninitialized Constant BlahBlah (NameError)

Error Stage:

Development

Error Location: 

Code has a reference to a name starting with an UPPERCASE (CAPITAL) character and it was referenced (used in right hand side of assignment, OR as a input parameter in a method etc) even though no value was assigned yet.

Error Detail: 

Names starting with UPPERCASE characters in Ruby indicates constants.
Error Fix: 
Fix the constant so that it gets a value assigned before referencing it.
Error Fix2: 
If the name is not expected to be constant, rename it accordingly.

Hints - 01 - Cheatsheet

PDF file with all good hints about "Ruby On Rails":
http://www.blainekendall.com/uploads/RubyOnRails-Cheatsheet-BlaineKendall.pdf

Troubleshooting - 01 - Unknown database

Error Message: 

#42000Unknown database 'timesheet_development'

Error Stage:

Development

Error Location: 

URL. http://localhost:3000/timesheet

Error Detail: 

Was mentioned in C:/rails/timesheet/database.yml file.

Error Fix: 

Correct C:/rails/timesheet/database.yml file to use correct database name.

Error Fix2: 

Had to bounce the WeBrick server.