Why do I sometimes get "Could not load file or assembly AjaxControlToolkit version 3.0"?

Question

We recently published a new version of asp.net, where we changed from AjaxControlToolkit version 3.0 to 3.5.

I checked the website and found that it was working fine.

The next day, I received the following two similar exception reports, which appear to be related to a version change:

Failed to load file or assembly 'AjaxControlToolkit, Version = 3.0.20229.20843, Culture = neutral, PublicKeyToken = 28f01b0e84b6d53e' or one of its dependencies.

The installed assembly manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)

Request information:

1) Request URL: http://.../Default.aspx? _TSM_HiddenField_=ctl00_sm1_HiddenField &_TSM_CombinedScripts_=%3B%3BAjaxControlToolkit %2C+Version%3D3.0.20229.20843%2C+Culture%3Dneutral%2C+ PublicKeyToken%3D28f01b0e84b6d53e%3Aen-US%3A3b7d1b28-161f-426a-ab77-b345f2c428f5%3Ae2e86ef9%3A1df13a87%3A8ccd9c1b http://.../Default.aspx? _TSM_HiddenField_=ctl00_sm1_HiddenField &_TSM_CombinedScripts_=%3B%3BAjaxControlToolkit %2C+Version%3D3.0.20229.20843%2C+Culture%3Dneutral%2C+ PublicKeyToken%3D28f01b0e84b6d53e%3Aen-US%3A3b7d1b28-161f-426a-ab77-b345f2c428f5%3Ae2e86ef9%3A1df13a87%3A8ccd9c1b 3B% 3BAjaxControlToolkit% 2C + Version% 3D3.0.20229.20843% 2C + Culture% 3Dneutral% 2C + PublicKeyToken% 3D28f01b0e84b6d53e% 3Aen-US% 3A3b7d1b28-161f-426a-ab77-b345f2c428f5% 3Ae2e86ef9% 3A1df13a87% 3A8ccd9c1b http://.../Default.aspx? _TSM_HiddenField_=ctl00_sm1_HiddenField &_TSM_CombinedScripts_=%3B%3BAjaxControlToolkit %2C+Version%3D3.0.20229.20843%2C+Culture%3Dneutral%2C+ PublicKeyToken%3D28f01b0e84b6d53e%3Aen-US%3A3b7d1b28-161f-426a-ab77-b345f2c428f5%3Ae2e86ef9%3A1df13a87%3A8ccd9c1b

2) Request URL: http: //.../Login.aspxReturnUrl=%2FUser%2FFaqPosting.aspx%3F _TSM_HiddenField_% 3Dctl00_sm1_HiddenField% 26_TSM_CombinedScripts_% 3D% 253B% 253BAjaxCont32% 252% 253% 253% 253% 253% 253% 253% 253% 253% 253% 253% 253% 253% 253% 253% 253% 253% 253% 253% 253% 253% 253% 253% 253% 253% 253% 253% 253% 253% of 252% 253% of% 233% by 252% of, 232% 253% 252% 253% 232% 252% 252%, 2% % 2 BCulture% 253Dneutral% 252C% 2BPublicKeyToken% 253D28f01b0e84b6d53e% 253Aen-US% 253A3b7d1b28-161f426aab77b345f2c428f5% 253Ae2e86ef9% 253A1df13887% 253A1df13b87c

(sm1 refers to asp.net ScriptManager)

I do not understand why these exceptions did not occur when I tested the website, but then occurred for some requests by some other users.

Do any of you know why this could happen? Or a hint of how I recognize?

Answer 1

I suppose this could be due to caching some content in the user browser, so the browser uses the old request URL. Or it could be a search engine trying to use an old saved URL.

Answer 2

---

I assume that you did not update the web.config file on the production server, and it still has links to version 3.0. This is the most common reason that I find for this type of error.

The second place to search is in separate files. Once you root out the wrong link, wherever it is, your problem should disappear. The important part is reviewing files that you don’t overwrite when publishing. web.config is the most comm.

Answer 3

Check if you have Panda or another firewall / antivirus. I have a problem with Panda recently. Good luck

Answer 4

This always happens to me because of permissions on the folder containing the DLL. Go there and give full control over the user account that asp.net runs on, and this should take care of that.

Answer 5

I would use the aspnet_regiis tool to reinstall the asp.net component in the .net framework.

Resources

http://msdn.microsoft.com/en-us/library/k6h9cz8h(VS.80).aspx

http://blogs.x2line.com/al/archive/2007/07/15/3203.aspx