If that happend first try !checkban <your nick> on playdota.eu channel.
If you arent banned but that still happend it might be a map problem. Recently new map comes up so you have to download a compatible (newest) version from getdota.com
Most people have problems with correct folder where map should be.
Sounds easy but map must be in "...\Warcraft III\Maps\.." or "...\Warcraft III\Maps\Download\.." folder.