Silverlight webapplication white screen of death - silverlight

I'm having an white screen of death when trying to debug my silverlight application. The problem is that I don't know what causes it and I don't get any type of information from either Visual Studio or the browser itself (IE9). Breakpoints won't be hit as App() in the App.xml.cs doesn't get fired either.
The application works fine on my own laptop, but I'm trying to make final adjustments to it on the server which will host the application once it's done. The problem occures on this server.
Would there be any way to get information about what's causing it or did someone experience simulair issues?

hit F12 in IE and go to network and start capturing. You should see your error there if something went wrong downloading and also if there was a problem with the Silverlight plugin (check Console or Script tag).

There could be a number of reasons for this including problems with database connectivity, WCF services, and many other factors. One thing that might help you get some information is a product called Fiddler. If you are able to download and install that on your development machine, you can have it running when you try and access your application on the server. It will give you messages for every step of your application initialization, including database authentication, service authentication, the xap file transfer, etc.

My problem was related to init params not loading up from the web project's .aspx page, try having a look at this if you are having "white death screen" issues.

Related

Difficulty with SQL Server 2014 training kit

Trying to work on this training kit to get educated with SQL Server 2014.
As seen here:
https://www.microsoft.com/en-ca/download/details.aspx?id=41700
I can't get it to work. It seems to come with a pdf explaining how to get it to work on your browser. Apparently by default the browser (chrome) won't run "application that use XML configuration files when they are run from a local computer" The only way to get it to work is by placing "--allow-file-access-from-files" to the google chrome shortcut properties window in the "target" location.
Even after doing all this I still get a message saying "network error" and the message on the top of the screen on the browser saying "To run this page in google chrome, close Chrome then create a shortcut with the --allow-file-access-from-files" property on..." (basically telling me to do the thing I just did following pdf instructions the kit came with)
Does anyone know what is going on?
Thanks in advance.

ASP.NET single page application or MVC app and 404.15

I created a ASP.NET single page application. When I run it I get the following 404.15 error. I see the same error with an MVC application without a Web API in it also.
I commented out the ConfigureAuth code as below:
public partial class Startup
{
public void Configuration(IAppBuilder app)
{
//ConfigureAuth(app);
}
}
Now I get another error which is below:
I tried to duplicate this on a different laptop, and I don't see a problem there.
Is this a directory level permission issue on this particular laptop where I created the app? Appreciate anyone can shed some light on this to fix this.
UPDATE 11/9/2014
I did some further debugging and found that the applications works fine with no authentication and Windows Authentication. When the authentication is forms, I see this problem happening. As you see in the IntelliTrace, the GET request is looping back to Account/Login multiple times and finally give with a 404.15 error. I added a authorization section in the web.config to allow all users to access the resources with , I still see the errors.
I see a major difference between how my laptop and the surface pro 2 behaving with the same application. In my surface pro 2, the home page is displayed and the redirect to account/login never happens. But in the laptop the redirection is happening to account/login.
There are tables in the surface pro 2 created by the asp.net identity. But in my laptop there are no tables. I believe when the application starts, there is no requirement for the tables and the control should go to the home page.
I hope anyone can provide an answer with my additional info.
At first sight looking at the requestedUrl it may be the case that you are always redirecting to the same page (the login page) which creates an infinite redirect loop until the request url becomes too long: Since there is no code I can't be sure about it but I would suggest you to check your redirect url. The authentication appears just because you outcommented the ConfigureAuth method but I don't think it will solve the problem.

Unable to access a simple web application (running on Tomcat Server) from another System

I have written a simple web Application which is running(on Tomcat Server) fine on my local system.But when I tried to access from a different system using http:/my_ip_address:8080/Projec1/My_Application. Its showing this error
Network Error (tcp_error)
A communication error occurred: ""
The Web Server may be down, too busy, or experiencing other problems preventing it from responding to requests. You may wish to try again at a later time.
I know many of you must be well versed with this kinda error.But for me its kinda new.I would be happy if you state possible reason and solutions(Please tell me if there is configuration is required in Server step wise)
Thanks All
I forgot tell you all that i found the answer of above question, actually there was proxy setting problem.This is what i did
Open internet option in IE.
Goto LAN setting in Connection option.
In LAN Setting there is advance setting tab, click it.
You will see a Exception box at the bottom.
Type the IP Address form which you want access.
eg. 10.200;*.xyz.com
This setting is to be done on system from where you want to access your web application.
Starting IP address where application is running 10.200.---.--- that is why in exception box it is mentioned as 10.200;*.(your Interanet Server Name)
Hope this will help.
Thanks

Silverlight WSOD at remote client site

I have a client who installed our silverlight app recently. it works fine from their server itself. but when they try to run it from a client, they can log in through the aspx login page, but on the main page, which hosts the tag and the .xap file, they see absolutely nothing!
I cannot see their screens, just get occasional screenshots via email and cross my fingers that they are typing the URL I tell them to. Even Shareview is not working for them - they can see my screen but I cannot see theirs.
So I am pleading - help! Please throw out some wacky ideas. I just learned an hour or so ago that they did not even have silverlight installed, so the mornings debugging effort was a waste of time. So who knows what the next fascinating source of problems is?
Here is the user-agent info. Oor app is .net 4.0 could that be the problem? It does noty look to my untrained eye that the client supports 4.0 (from the web server log):
Mozilla/4.0+(compatible;+MSIE+7.0;+Windows+NT+5.1;+.NET+CLR+1.1.4322;+.NET+CLR+2.0.50727;+.NET+CLR+3.0.04506.30;+.NET+CLR+3.0.04506.648;+.NET+CLR+3.0.4506.2152;+.NET+CLR+3.5.30729) 401 3 5 0
Getting closer - I see that the GET request for the XAP is returning 401 - not found! What would do that?
It's very possible that they are blocking XAP files either directly or indirectly at the firewall. XAP files are simply ZIP files and inspection-based firewalls tend to look at these as a security risk. You may want to see if they can setup an exception in their rules.
Hmm..
1) check if your client access the good url. Request their IP address, then check the web server logs. ie: are they requesting the good url, are they downloading the xap? (check if they use a proxy, too?)
2) check that they restarted their browser after installing the Silverlight runtime.
3) Do you handle the UnhandledException event for your Application class? If no, use it to send detailed exception logs to your server on application crash.
4) Use javascriptto initialize your Silverlight application. This way, you can be notified if the runtime fail to start, (for example if it failed to load the xap file) You can use ajax to report the issue to the webserver.

Calling a https WCF-Service from Silverlight 4 only works with fiddler and from VS2010

for days now, I try to get the following scenario running:
I have a Silverlight 4 Application that calls a WCF-Service via HTTPS. The WCF-Service is located on one of our servers, the Silverlight 4 app is also served from this server. After several hours of trial and error (well actually more error than try) I get it running when starting it from my VS2010 development environment on my local machine (see also SecurityError when calling a HTTPS-WCF Service from Silverlight 4).
But ...
The call to the https-WCF ONLY works when I start the SL-App from my VS2010 AND when fiddler is running and after I tell fiddler to ignore the Certificate Error (I use a self-signed certificate). When fiddler is not running, I get a security error. That applies, when my browser is the IE. When I copy the localhost address from the IE and paste it in my opera, it works without fiddler.
When I deploy the Silverlight app to the server and call it from the server, the WCF-call doesn't work, whether fiddler is running or not. I just get the standard Message, that an exception has occurred. This happens in both Opera and IE. Fiddler doesn't ask me to ignore the Certificate Error like it does in the VS2010 scenario, so maybe there is somewhere the key to my problem. Unfortunately, I have not much experiences with this stuff, so I have no idea, where to look or what to do.
I already found something about the fiddler issue here on stackoverflow ( Silverlight Requests, Failures & Fiddler), but it doesn't help me solving my problem.
I hope that some of you can shed some light in this issue, before all my hair is turned to gray.
Thanks in advance,
Frank
Edith has just installed the Certificate as a trusted Certificate in IE - but I still get the error, when calling the WCF when starting the deployed silverlight app from the server. At least I can call the Service when I start the SL app from VS2010 in the IE now (even when that doesn't help me, when some one else has to work with the app.
Several thoughts:
What is the exact error message you're seeing? Any inner exceptions?
Could this be a cross-domain issue? (Are the Silverlight XAP and the WCF service hosted from exactly the same domain, including its HTTP vs HTTPS characteristic, port number, distinction between "localhost" and an actual machine name, etc? What is the exact address as it appears in ServiceReference.ClientConfig or in code, and does its domain name exactly match the XAP's domain name?)
Do you see any call attempting to go through in Fiddler at all when it fails? (If not, I would strongly suspect a cross-domain issue)
If you manually browse to the https://....../YourService.svc from IE/Opera (instead of invoking the service through code in Silverlight), can you successfully see the service information page, with no certificate warnings/errors?
Does your SSL certificate has the same name as your service host? If not, that causes an error which can lead to the described behavior

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