asp.net mvc - Saving file to App_Data doesn't seem to work when app is uploaded to Azure -

i have small mvc 5 app, , point works fine in localhost, when publish azure, parts doesn't work. example, have in view:

<div class="form-group">        <div style="position:relative;">             <label>image</label>             <a class="btn" href="javascript:;">             choose file...             <input type="file" name="image" accept="image/jpeg, image/png"                       style="position:absolute;z-index:2;top:0;left:0;filter: alpha(opacity=0); opacity:0;background-color:transparent;color:transparent;"                        onchange='$("#upload-image-info").html($(this).val());' />            </a>            <span class="label label-info" id="upload-image-info"></span>        </div> </div> 

so, in server side have this:

    public actionresult servicerequest(requestviewmodel rvm, httppostedfilebase image = null, httppostedfilebase video = null)     {         tmppicturepath = server.mappath("~/app_data/uploads/images");         tmpvideopath = server.mappath("~/app_data/uploads/videos");          // check properties, , save file         filename = path.getfilename(image.filename);         imagepath = path.combine(tmppicturepath, filename);         image.saveas(imagepath);          // afterwards, give imagepath sendgrid attachment mail         message.addattachment(imagepath);          // , later in code, send mail         transportweb.deliver(message);      } 

please note omitted parts of code above, make more clear want do. point in localhost, works fine, able select file , after uploading it, sends via e-mail. but, when publish website on azure, , try same thing, when press button seems uploading file, afterwards error message saying:

error. error occurred while processing request.

i don't know whether cannot store files on server, or cannot read them afterwards attachment, or cannot send mail. idea problem may be?

i connected ftp server , manually created folders, worked okay.