Searching in current project does only work if a file is open

I wanted to find a string in a newly opened project and did the following:

• Start Creator
• open a project
• Hit Ctrl-Shift-F to open the search dialog

Result:
I got a search dialog with scope "current project" which is inactive: I can not enter and string to search for

Expected Result:
I expected to be able to search the newly opened project for the string.