Could not load file or assembly CMS.Core after upgrade form 8.2 to 9

Ha Son Nguyen Tat asked on April 4, 2016 13:13

In current time, I've gotten this error after upgrade site form 8.2 to 9

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Hope you to support for me! Thank you so much!

Recent Answers


Anton Grekhovodov answered on April 4, 2016 13:40

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Brenden Kehren answered on April 4, 2016 13:53

Check in your Bin directory, you're most likely missing the CMS.Core.dll. If you are, then go up one level to the /Lib directory and copy it into your project.

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Felix Planjer answered on April 4, 2016 14:40

We had the same problem. Turned out that when deploying to Azure, our deployment tool did not remove existing files. This was intended, because otherwise also the Website folders with media library files etc. would be removed.

Because of this, after the upgrade some old DLL DLL files, referencing CMS.Core from version 8 were left behind. Also note that there are files in other folders that can break your upgraded website if they are not removed. We came across some ashx files (like GetResource.ashx) that do not exist anymore. If they are left in you v9 website css and js files cannot be served anymore.

We ended up deleting everything from the WebApp folder, except App_Data and some WebSite folders. then redeployed and everything started working.

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giang le answered on April 5, 2016 05:18

What is your deployment tool?

"We ended up deleting everything from the WebApp folder, except App_Data and some WebSite folders".

Can you explain details your solution? We will use a FTP tool to connect to Azure server and delete all files (web.config, global.asax,...) and folder and only keep App_Data and folder that start with "CMS", right?

Do you have other solution? It seem this solution is not safe.

I have check version of CMS.Core in "bin" folder and it is "9.0.5809.18510" so I think the project did not reference to it.

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giang le answered on April 7, 2016 05:36

@Felix Planjer: Can you help me answer my questions above? :(

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Brenden Kehren answered on April 7, 2016 14:09

Did your upgrade succeed when you ran the upgrade tool? Were there any errors in the event log? If it didn't succeed then you most likely will receive this error because not all the files were updated. In this case, it appears the CMS.Core.dll file is of version 8 and not 8.2 or 9.0. You can check this in the properties of the .dll itself. Compare a few .dll's and if they are incorrect, check in your LIB directory and see if those are updated to the proper version. If so, copy and overwrite them in the BIN directory on your website.

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Felix Planjer answered on May 30, 2016 15:46

We use Octopus to deploy and added a script to it, that removes all folders (via FTP) we specify. These are the bin folder and everything starting with CMS. Just be careful with deleting all folders starting with CMS, because Kentico creates folders for storing files for a sit. If your SiteName starts with CMS it will be also be deleted. That's why we don't simply delete CMS*, but make a delete statement for every folder we want to delete (CMSWebParts, CMSModules, CMSAdmin, ... etc)

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