Welcome to the Splat alpha!

I'll need more info to diagnose this. Can you edit your reviewboard install's reviewboard/webapi/resources.py file, find the "create" function in ReviewRequestResource, and look for:

        except SCMError:
            return REPO_INFO_ERROR
 
Change this to:

        except SCMError, e:
            logging.error("Got SCMError when creating review request: %s" % e, exc_info=1)
            return REPO_INFO_ERROR

Then restart and try again. The log should should contain more useful information.

• Status:

  +	NeedInfo

• Tags:

  -	Priority-Medium
  +	Priority-High
  +	Milestone-Release1.6.x

• Assigned to:

  +	chipx86

What I found in the log was the following, I dont know is it helps or not:

Internal Server Error: /api/review-requests/
Traceback (most recent call last):
  File "/usr/local/lib/python2.6/dist-packages/Django-1.3-py2.6.egg/django/core/handlers/base.py", line 178, in get_response
    response = middleware_method(request, response)
  File "/usr/local/lib/python2.6/dist-packages/Django-1.3-py2.6.egg/django/middleware/http.py", line 15, in process_response
    response['Content-Length'] = str(len(response.content))
  File "/usr/local/lib/python2.6/dist-packages/Djblets-0.6.9-py2.6.egg/djblets/webapi/core.py", line 276, in _get_content
    content = adapter.encode(self.api_data, request=self.request)
  File "/usr/local/lib/python2.6/dist-packages/Djblets-0.6.9-py2.6.egg/djblets/webapi/core.py", line 88, in encode
    return super(JSONEncoderAdapter, self).encode(o)
  File "/usr/lib/python2.6/json/encoder.py", line 367, in encode
    chunks = list(self.iterencode(o))
  File "/usr/lib/python2.6/json/encoder.py", line 309, in _iterencode
    for chunk in self._iterencode_dict(o, markers):
  File "/usr/lib/python2.6/json/encoder.py", line 275, in _iterencode_dict
    for chunk in self._iterencode(value, markers):
  File "/usr/lib/python2.6/json/encoder.py", line 317, in _iterencode
    for chunk in self._iterencode_default(o, markers):
  File "/usr/lib/python2.6/json/encoder.py", line 309, in _iterencode
    for chunk in self._iterencode_dict(o, markers):
  File "/usr/lib/python2.6/json/encoder.py", line 275, in _iterencode_dict
    for chunk in self._iterencode(value, markers):
  File "/usr/lib/python2.6/json/encoder.py", line 294, in _iterencode
    yield encoder(o)
UnicodeDecodeError: 'utf8' codec can't decode byte 0xf3 in position 10: invalid continuation byte

Now I am sure that there are two errors here. One with the ChangeNumberInUseError, and one with international characters in the Perforce description.
Now I can reconstruct the history around this bug:
 - We tried to post-review a change with international characters but we failed by Unicode problems.
 - Then we re-try the post-review and consistently failed with the mysterious SCMError error I entered originally.
 - I entered the bug into the tracker. You suggested me the patch for better error reporting. I applied the patch and tried another post-review. Then I hit and reported the Unicode problem again (see comment 3)
 - Now I hit the SCMError again, and with your patch I located the better error reporting in the log.
Here it is:
Got SCMError when creating review request: None
Traceback (most recent call last):
  File "/usr/local/lib/python2.6/dist-packages/ReviewBoard-1.6rc2-py2.6.egg/reviewboard/webapi/resources.py", line 5657, in create
    changenum, local_site)
  File "/usr/local/lib/python2.6/dist-packages/ReviewBoard-1.6rc2-py2.6.egg/reviewboard/reviews/managers.py", line 96, in create
    raise ChangeNumberInUseError(review_request)
ChangeNumberInUseError: None

But to tell the truth, seeing the code I don't understand what is the problem.
Please fix both problems!

I missed to mention that we really tried to upload the same change twice. But the error message about the extended information misleading and not helpful.

• Status:

  -	NeedInfo
  +	Duplicate

• Duplicate of:

  +	2047 - UnicodeDecodeError: 'utf8' codec can't decode byte with non-utf8 characters in perforce description