Failed to install dhtmlx calendar

I can get dhtmlx calendar demos to work on my local hard drive, but when I install the same code on my website I get part of the template and then an error with failure to display the calander.

error: ‘scheduler’ is undefined

Any thoughts?

Most probably js file was not loaded correctly. Doublecheck that script tags points to the correct location and the case of file name is exactly the same in html code and on filesystem.