Sqlite3 gem not loading, gem installed and specified in project
I just had this issue too. Go into your Gemfile.lock file and search for the 'sqlite3' entry. You'll note it reads sqlite3 (1.3.8-x86-mingw32). Change that to sqlite3 (1.3.8-x64-mingw32) and then run the bundle install command and everything should work like normal.
I faced same issue and this seems to be Windows 7 specific Env issue. My problem was resolved with below changes
Go into your Gemfile.lock file and update sqlite3 (1.3.8-x86-mingw32) to sqlite3 (1.3.8-x64-mingw32)
Run bundle install from the project directory. That will update Gemfile.lock. You also have to restart the Rails server.
Also see config/database.yml which specifies which gem to use for the database.
development: adapter: sqlite3 database: db/test.sqlite3 pool: 5 timeout: 5000