Exception raised by tbwiki software

Traceback (most recent call last):
  File "fuego-1.2.cgi", line 70, in 
    main(req)
  File "/home2/birdorg/work/tbwiki/cgi-bin/tbwiki_engine.py", line 2762, in main
    patc = re.compile(".*"+search_string)
  File "/usr/lib64/python2.7/re.py", line 190, in compile
    return _compile(pattern, flags)
  File "/usr/lib64/python2.7/re.py", line 242, in _compile
    raise error, v # invalid expression
error: multiple repeat