Hata detayını görebilmek için site root'una bir web. config dosyası oluştur ve içine şunları yaz. Kod:

Merhaba Arkadaslar, Sitemde Admin panelinden Resim Upload yerine girdigim zaman, upload edicegim sirada bu hatayla karsilasiyorum. Yardimci olabilecek olan varsa sevinirim.. Description: An application error occurred on the server. The current custom error settings for this application prevent the details of the application error from being viewed remotely . It could, however, be viewed by browsers running on the local server machine. Details: To enable the details of this specific error message to be viewable on remote machines, please create Details: To enable the details of this specific error message to be viewable on remote machines, please create a &lt;customErrors&gt; tag within a &quot;web. config&quot; configuration file located in the root directory of the current web application. This &lt;customErrors&gt; tag should then have its &quot;mode&quot; attribute set to &quot;Off&quot;.