So i Deployed an umbraco for a client and everything looks fine untill they updated some content, and now the admin section gives and error right after loggin in.
Server Error in '/' Application.
Value cannot be null.
Parameter name: source
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.ArgumentNullException: Value cannot be null.
An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.
[ArgumentNullException: Value cannot be null.
Parameter name: source]
System.Linq.Enumerable.SingleOrDefault(IEnumerable`1 source, Func`2 predicate) +2535654
umbraco.cms.presentation._umbraco.Page_Load(Object sender, EventArgs e) +63
System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e) +51
System.EventHandler.Invoke(Object sender, EventArgs e) +0
System.Web.UI.Control.OnLoad(EventArgs e) +92
umbraco.BasePages.BasePage.OnLoad(EventArgs e) +14
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +772
So asumming that this is a caching problem i deletede the umbraco.config file, edited the web.config and ran the /umbraco/dialogs/republish.aspx?xml=true url.
but the problem seems to not be effekted by caching.
Im having the same issue on my local with Umbraco version 4.11.1
I dont remmebr having updated any content the other day when everything was working. Today just when i tried to loging to admin im keep getting this error!
Refer to this post
Fixed my issue (after copying config file from my backup)
Oh, i totally forgot to get back to this one, but yes it semse that multiple files had been corrupted, and unreadeble or no longer beening .config files, i did a full upload of systems files for umbraco and everthing worked agian.
I can confirm that I had the same problem and redeploying the config files from backup resolved it for me too.
Thanks Abtin & Morten!
I have got the same error on 4.9.0 as well - and solved the problem by redeploying the config files.
This has never occured on our primary webhotel partner (Scannet) and this happens after the site has been online for about 6 months on another webhotel partner (Binero)
Anybody knows why this happens?