B1if :HTTP error :could not PROPFIND file '/B1iXcellerator/exec/dummy'

hi,

I try to add a new URL to the project, but he sent me the following error:

HTTP error: could not PROPFIND file '/ B1iXcellerator/exec/dummy' on server 'localhost' (403)

I use AltovaXMLSpy

Will someone an idea