Dewman a quick internet search brings up 100's of posts on this error so it seems to be fairly common, especially with third party glass. Most seem to recommend cleaning the contacts with a soft cloth. Failing that there is likely an issue internally with the lens.
There are some really hilarious suggestions that are supposed to work. Check this thread:
Err 01 - Communications between the camera and the lens... (both 7D and 60D): Canon EOS 7D / 10D - 80D Talk Forum: Digital Photography Review Made me laugh.
Bottom line, it is a failure to communicate. Clean the contacts, if that fails then send it back.