Twitter wont let me tweet to people?

[Runkidrun]

I tried tweeting to my friend on twitter but its not letting me :/ I type the persons account name like @merelyRBLX (his exact name)

but it wont let me! pls help ill give five stars

[Bruce]

CANT USE TWITTER ?
CHROME & AVG users apply following:
- Customize and Control Google Chrome
- Tools
- Extensions
- AVG Secure Search (You Can Leave Enabled)
- AVG DoNotTrackOptions
- Remove Tick from "TwitterButton" found in the list
- Save