ERROR: While executing gem ... Invalid spec cache file in C:/Users/...

L:xampphtdocsframeworksyii2framework>gem update --backtrace
Updating installed gems
ERROR:  While executing gem ... (Gem::Exception)
    Invalid spec cache file in C:/Users/Larry/.gem/specs/rubygems.org%443/specs.4.8
        C:/Ruby200-x64/lib/ruby/site_ruby/2.0.0/rubygems/source.rb:187:in `rescue in load_specs'
        C:/Ruby200-x64/lib/ruby/site_ruby/2.0.0/rubygems/source.rb:179:in `load_specs'
        C:/Ruby200-x64/lib/ruby/site_ruby/2.0.0/rubygems/spec_fetcher.rb:266:in `tuples_for'
        C:/Ruby200-x64/lib/ruby/site_ruby/2.0.0/rubygems/spec_fetcher.rb:228:in `block in available_specs'
        C:/Ruby200-x64/lib/ruby/site_ruby/2.0.0/rubygems/source_list.rb:97:in `each'
        C:/Ruby200-x64/lib/ruby/site_ruby/2.0.0/rubygems/source_list.rb:97:in `each_source'
        C:/Ruby200-x64/lib/ruby/site_ruby/2.0.0/rubygems/spec_fetcher.rb:222:in `available_specs'
        C:/Ruby200-x64/lib/ruby/site_ruby/2.0.0/rubygems/spec_fetcher.rb:102:in `search_for_dependency'
        C:/Ruby200-x64/lib/ruby/site_ruby/2.0.0/rubygems/commands/update_command.rb:113:in `fetch_remote_gems'
        C:/Ruby200-x64/lib/ruby/site_ruby/2.0.0/rubygems/commands/update_command.rb:135:in `highest_remote_version'
        C:/Ruby200-x64/lib/ruby/site_ruby/2.0.0/rubygems/commands/update_command.rb:264:in `block in which_to_update'
        C:/Ruby200-x64/lib/ruby/site_ruby/2.0.0/rubygems/commands/update_command.rb:260:in `each'
        C:/Ruby200-x64/lib/ruby/site_ruby/2.0.0/rubygems/commands/update_command.rb:260:in `which_to_update'
        C:/Ruby200-x64/lib/ruby/site_ruby/2.0.0/rubygems/commands/update_command.rb:96:in `execute'
        C:/Ruby200-x64/lib/ruby/site_ruby/2.0.0/rubygems/command.rb:305:in `invoke_with_build_args'
        C:/Ruby200-x64/lib/ruby/site_ruby/2.0.0/rubygems/command_manager.rb:167:in `process_args'
        C:/Ruby200-x64/lib/ruby/site_ruby/2.0.0/rubygems/command_manager.rb:137:in `run'
        C:/Ruby200-x64/lib/ruby/site_ruby/2.0.0/rubygems/gem_runner.rb:54:in `run'
        C:/Ruby200-x64/bin/gem:21:in `<main>'