HTML Help Compiler Error HHC3004

Today i had an error by building my sandcastle documentation project.

After compiling during opening the output instead my chm-file in the help viewer the internet explorer pops up with an error message that the destination could not be found. So i took a look in the log of the compile process and there was some warnings of the following type listed:

HHC3004: Warning: Resources.HandlingCursors.01.png :
The HTML tag <CRYPTICAL SIGNS> is not a valid HTML tag (it does not begin with an alphanumeric character).

After google this i got the hint, that in filenames with multiple dots no part should start with character “H”!!! So HandlingCursors was the problem.

After renaming in Resources.Cursors.01.png everything works fine.