Error Xibo Client Options

I have installed xibo in IIS 8.5 Windows server 2012, when I install the client on a pc and save the settings I throw the following error
The client found the content type of response from ‘text / html’, but was expecting ‘text / xml’.
The request failed with the error message:

<! DOCTYPE html PUBLIC “- // W3C // DTD XHTML 1.0 Strict //” “”>

500 - Internal server error.

Server Error

500 - Internal server error.

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