When you publish a Crystal Report file or document to Ripplestone you are moving the physical file from the local storage to the web server. Ripplestone has a default file size of 10 MB, so report files that are larger than 10 MB will not upload.
This size can be changed in the web.config file located in C:\Sites\Ripplestone. The web.config file is an XML file that can be edited with any text editor or XML reader. Look for the httpRuntime section and change the maxRequestLength to whatever value you would like (1024 = 1MB).
Below is an example of the httpRuntime section with the default values that come with Ripplestone.
<!—Sets the max size for file uploads: 102400 = 10MB and 3600 = 1 hour -->
<httpRuntime maxRequestLength="10240" executionTimeout="900" requestValidationMode="2.0"/>