emacs reftex hangs up while Scanning bibliography database

[schury . michael]

I've a strange reftex-issue. When i insert a cite from a bib-file, emacs hangs 
up. I've tried this on two different machines: Windows 7 and on Mac OS X. (GNU 
Emacs 24.5.1)

Insert a cite is done:
1. Open emacs, the bibliography file is loaded with:

(setq reftex-default-bibliography
        
'("/Users/user/CloudStation/repositories_d/pandoc-templates/examples/socbib-pandoc.bib"))
( the bib file exists and is accessible)

2. Open a .tex file and press C-c [ ^M and enter b*.

Now emacs shows the message:

Scanning bibliography database socbib-pandoc.bib

No emacs hangs up. Does anyone have an idea why ?

I've tried this with different bib files (so the bib file itself should be OK).