Please provide the link which you are using.
In general this error happens, when you install over vm1.1 and some old vm1.1 files are read. When you update vm1.1 the file toolbar.php should be renamed to toolbar.vm1.php,
please test first if the file is renamed, if yes, please delete the file and try again.
If this does not help, I need exactly the link you are using, so that I can reproduce the error. Maybe more files must be deleted.