I recently updated to the latest gem version of Rails, and I kept
getting odd errors through my code. In every case I cleaned them up by
re-starting the server.
The errors were usually in .rhtml files and talked of illegal
characters, generally pointing at whitespace.
I've been through a few editors and IDEs before settling on Rub In
Steel. (I just like Visual DevStudio. It feels like home.) Turned out
my tabs were a bit of a mess... These days I default to the tab key
spitting out two spaces.
After getting sick of constantly re-starting webrick, I did a global
replace on tabs, turning them into double spaces.