Several times a day I receive this error while running my asp.net mvc4 project. I am not asking what that means, or how to fix it, but what am I doing to cause it? It is really starting to bug me, and if I can cause it to go away by altering my workflow I will.
Cannot create/shadow copy '< assembly >' when that file already exists.
As I mentioned above the project is an MVC4 application. My workflow is typically.
Make a change (code or html)
If it was code, rebuild the project (using keyboard shortcut CTRL+SHIFT+B)
refresh the page
see annoying error
clean the solution
rebuild solution
refresh page
verify change
goto 10
(I get the error with/without the debugger attached.) I will be eternally grateful to anyone who can inform me on how to avoid this error, and will promptly tweet your praises
I find this annoying too. It seems to happen when you try to refresh the page in a browser before the build is fully complete. Try counting to three-one-thousand after build is complete and then refresh in the browser. Create/shadow copy should be done by that point.
I also don't think you should need to "clean solution". I believe a rebuild is a clean + build, so you may be cleaning twice.
After a bit of research, I also found this pre-build event which seems to be popular. (this workaround does not seem to work, perhaps it did in previous versions of VS / .NET framework)
Update: alternate solution
Another way to get by this is, when you see the YSOD, just type in a different URL in the browser and load it instead. Then click the back button and refresh to get to the page you were trying to reload in the first place.
What's causing this error seems to be doing the shadow copy (stating the obvious...), ie generating a file in one folder and then reading it to copy it elsewhere. I think what's causing the issue is generating or not that first file, and when/how it's copied, regardless of what your actions are. Does this first file (that will be shadow copied) needs regenerating, and therefore re-shadow copied?
This post says:
By default shadow copy is enabled on every appdomain created by ASP.NET. Assemblies loaded will be copied to a shadow copy cache directory, and will be used from there. So that the original file is not locked and can be modified.
And their fix is to prevent shadow copy. But I don't personnally fully understand what shadow copy does in the asp.net context, maybe someone can clarify if there are any bad side effect to disabling it:
<configuration>
<system.web>
<hostingEnvironment shadowCopyBinAssemblies="false" />
</system.web>
</configuration>
This post talks about disabling indexing and/or antivirus, which would suggest that building the project generates new files, and the antivirus (or indexing service) accesses them and locks them, just when the shadow copy is trying to copy that exact same file.
I get his error regularly and never found what specific action I do causes the error. I make a code change, press F5 (Run/ Play button), get the error in the web browser, close the web browser, press F5 again. It now works. I don't clean, I don't rebuild. However, with the second F5/Run, I believe VS detects there's been no code change, and therefore, maybe the shadow copy is not redone? Or maybe this time the shadow copy is timed slightly differently and it works.
I received this error after adding a new image to my web project.
In VS, each image has a property entitled "Copy to Output Directory". I chose "Copy Always", then I got the message.
I changed it to "Do Not Copy" - now it is happy.
Hope that helps someone.
Related
I've come across an unbelievably stupid situation with my ASP.NET MVC application hosted in IIS 7.5. Here's the case:
I publish the application to the server and test it. It works just fine
I change anything in the web.config file and then undo the change. So it's in its original state
I test the application again but this time I get
Could not load file or assembly 'file:///C:\Windows\Microsoft.NET\Framework64\v4.0.30319\System.Data.dll' or one of its dependencies. An attempt was made to load a program with an incorrect format. error.
Please note this: I just open the web.config file and edit and then immediately undo that edit. It doesn't matter in which line of which section I make edit. (After all, aren't configuration files there to not have to touch the code?)
Now comes more interesting part.
I copy and paste the latest published files to the application folder
test the application: Still get the same error
I republish the application and copy/paste to the folder, EXCEPT FOR THE WEB.CONFIG FILE. So I don't even touch the "damaged" config file.
Test it, voila, it works.
I just don't get it. Do you have any clue about this issue?
The problem was caused by a third party tool called EntityFramework Profiler with which I traced SQL commands issued by Entity Framework. After removing it from the application, the problem disappeared.
PLEASE NOTE: None of the answers in the link above (which I don't seem to be able to remove) helped me. As I explain below, I had already tried all that stuff
I have a web site, developed in VS2013 using ASP.NET MVC5/WebAPI2, which has several related projects such as a service layer, repository layer, etc. Down at the bottom of the stack is a class library that holds an EF model. I have separated the actual entities into another class library, to allow them to be reused without requiring the model library.
All of this has been working fine. The web site was running, and I could make calls to the WebAPI methods as well.
I just uploaded the latest version to the production server, and all is working fine there. Then came back to VS to carry on work, and when I try to run up the web site, I get an exception
Unable to load the specified metadata resource
Searching around, it seems that the cure for this is to modify the connection string to point to the actual assembly name instead of using the default . I have two problems with this, first is that none of the config files in the solution have been touched today (by me at least, and the file history form source control confirms this), so there's no reason why it should suddenly stop working after being deployed, and second, even if I add the assembly name, I get the same exception.
Anyone any ideas what I can do? I'm completely stuffed now. Can't do anything.
Edit: I tried again to specify the assembly in the connection string, and now get the exception Unable to resolve assembly. I have checked the assembly name in a decompiler, and I'm pretty sure got it right.
Edit again: I just pulled the version that I deployed from source control, and that gives the same exception, so I'm sure this is nothing to do with any files I've changed (or even that have been changed by VS). The version on the production server is still working, but the source code that drives that exact same version gives the exception. So, I'm certain that the answer is NOT to be found in the myriad other versions of this question, but is somewhere else.
Found the problem, and am posting it here in the hope that it will help someone else, as I don't think this was clear in any of the other posts on this issue.
I have a layered solution, with the web project referencing a service layer, which references a repository layer which in turn references the model project. It seems to for EF to work, whichever layer actually causes the database to be accessed requires a reference to the model project. My service layer project, which was where ToList() was being called (thus enumerating the query, and causing the database to be hit) didn't have a reference to the model project, so was failing to load the assembly.
I didn't need to alter the metadata part of the connection string either, as once the service layer had a reference to the model project, it was able to find the resources by itself. Having said that, one thing I did learn from all of this is that you can speed up the creation of the model (slightly) by specifying the assembly containing the resources explicitly, as this saves the framework having to search through all loaded assemblies to find them. I'm not sure if this will make any noticeable difference, but it can't harm.
I still can't explain how this had been working up until now, and suddenly stopped, as I hadn't changed any references, nor the way I was doing the data access. Still, it seems to be working now, which is all that matters.
Hope this helps someone.
Update It appears I have to rebuild/redeploy the app to see the changes. Anyone know why I have to do this? It's a static .xhtml page. Coming back to update, looks like I just have to stop/restart the server, not a rebuild. I was dumb and didn't try that first, mostly because I have to rebuild/deploy often anyways.
I'm working on a JSF 2 app that uses f:subviews. I'm on one subview where my changes aren't reflected in the UI when I refresh the browser. I've worked on other subviews where I don't have this problem.
I have a batch script which copies my .xhtml files into my installed apps folder. The batch script reports the file is copied over. It's business as usual... If I drill down into this particular installed app, I see my change in the file. Again, seems like business as usual. The change is not reflected in the UI when I refresh, however.
These are simple text changes I'm making, but not seeing.
The problematic subview doesn't appear to be anything special, it's just a p:datatable that's included via a ui:include with a couple of parameters for the data and to give it a unique id. If I replace the p:datatable with just simple text, the "old" table still shows up in the UI when I refresh. I just can't get any changes in this subview to be reflected in the UI.
Console doesn't throw any errors.
I'm using WebSphere 7.0.
Never encountered this problem before. It isn't a browser caching issue as I can edit other subviews and see those changes when I refresh the page.
Anyone have any ideas?
Each time I make a change to an Umbraco template and press Save, I get the confirmation popup saying:
Template saved
Template saved without any errors!
However, when I return to that template (click on another template and then back again), the changes have been lost.
I've ensured that the user account running my IIS application pool has Full Control over the \Views folder containing the .cshtml files (i.e. the Umbraco templates).
Strangely this just started happening, after it had been letting me make template changes with no problems. I can manually edit the .cshtml files on disk, but this seems ridiculous.
Any ideas?
A couple of things:
1) Have you checked that the following Windows accounts have full permissions for all folders "IUSR", "IIS_IUSRS", "NETWORK SERVICE" ?
2) Probably not but I have had problems in the past with caching. Have you disabled (set from True to False) caching properties in /config/umbracoSettings.config ? This should always be done during development.
OK, I'll provide an answer for others' future reference (although the reasons are unclear to me). It appears the change I was making to my Template must've been deemed invalid by Umbraco - when I strip the template text down to just a single, empty div and save it, the change is persisted successfully.
The confusing thing is that Umbraco provides no feedback as to why it's not saving - in fact it tells you that it HAS saved successfully.
Bizarre and confusing.
Just been editing my templates and got this problem. Fixed it by doing the following:
sign out of umbraco
clear your browsing data
sign back into umbraco
always be sure to copy and paste your code somewhere to keep it safe, and it can be easily pasted back in. Seems like a bug to me... but it saved after I did that.
(Using Umbraco 7)
Quite not sure why I see this error.
I navigate to my Login View like so http://test.staging.com/mywebsite/Login
My Login view was just redone using MVC but I have seen this same error message going to an aspx page as well...
If I use http I get the error message The specified request cannot be executed from current Application Pool.
If I use https://test.staging.com/mywebsite/Login, I'm good.
If I don't specify a protocol, test.staging.com/mywebsite/Login, I get the error as well
Is there an error happening under the covers and my custom error page can't be shown like discussed here?
What are some other causes of this error?
That usually means your custom errors are configured to run as a different AppPool.
You can read more at MSDN. (See section "Using Custom Errors from Another Application Pool").
There are two ways to correct this behavior. The first is possibly not one that you are interested in because it would require you to change your current architecture and run both sites in the same application pool (such as share the same worker process memory space). To do this, simply move the /errors virtual directory to run in the same application pool as the site for which it serves the custom error.
The second way is to make use of a registry key provided by IIS 6.0. This registry key makes sure IIS 6.0 does not check the metadata during the execution of the custom error and therefore allowing this to work.
See the article for information on the registry key fix.
It may also mean that you are using something along the lines of Server.Transfer to a page that is in a different AppPool.
It could be because you're using different versions of ASP.NET for one or many apps in the pool.
Make sure all apps in the pool use the same version of ASP (e.g. ASP 2.0.50727)
If you just added a new app, try changing the app momentarily to a different version of ASP, then back to same version. I experienced an issue where the displayed version was correct, but under the hood, a different version was used!
Check your event log, under Application, to get more details about the error.
The message would be caused by your page server-side redirecting to a page served by another application pool. Such as for example, in your link, the error page.
I know this is an old thread, but I stumbled upon it and found a different solution. Here's what worked for me: Make sure your application handles .asmx files correctly
From IIS:
Right Click on your project > Properties > Configuration
If necessary, add the .asmx file extension that maps to the aspnet_isapi.dll
Limit to: "GET,HEAD,POST,DEBUG" and restart.
Because I can't comment on vcsjones's answer, I'll add it down here. The DWORD value IgnoreAppPoolForCustomErrors needs to be set under HKLM\SYSTEM\CurrentControlSet\Services\W3SVC\ Parameters vs HKLM\SYSTEM\CurrentControlSet\Services\W3SVC referenced in that technet article. Set it to 1 and do an iisreset and you're good to go.
Source Blog Post
In my particular case, I received this error while trying to serve a content (non ASP.NET) website while it was an Application. Right-Clicking the virtual folder and removing the application fixed it for me.
In my case the application used the application pool that didn't exist. I have no idea how it's happened.