Document Viewer shows blank pages on some machines due to not being able to access system fonts.
In IIS, setting "Load User Profile" to true for the Application Pool will fix the problem. The problem is that it can not populate fonts from Registry if this setting is set to false. Note that by default IIS Application Pool's have this setting enabled.
After you do the change, make sure you clear the document cache (App_Data\DocumentCache) so that you force the Document Viewer to prepare the documents again, this time with access to fonts.
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