I recently started an upgrade of a Sitecore solution, and I came across an issue that I could not find any information about to help me resolve it.
If you read any of the documentation for upgrading sitecore you will eventually come to the step that indicates you must run <site>/sitecore/admin/UpdateInstallationWizard.aspx and load in the relevant .update file
I was running this to upgrade to Sitecore 7.5 initial release, and after verifying the installation package, I proceeded to do the installation. I watched the process and it very quickly processed the actions that it needed to processes. But then the process appeared to just hang. Chrome just showed the loading icon in the tab.
Looking at the folder on disk, PostInstallationErrors.txt was growing. Opening the file, there was 1000’s of entries for the following error:
Access to the path is denied
And occasionally it would mention a file. e.g.
Access to the path ‘D:\Websites\v2.0\Website\bin\System.Web.WebPages.Deployment.dll’ is denied.
Then reviewing the FileOperation.install.log, it would contain errors similar to:
System.UnauthorizedAccessException: Access to the path 'D:\Websites\v2.0\Website\bin\System.Web.WebPages.Deployment.dll' is denied. at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath) at System.IO.File.InternalDelete(String path, Boolean checkHost) at Sitecore.Update.Installer.Items.PostStepInstaller.FileOperationWorker.ProcessOperation(FileOperationInfo info)
Google was no help for me in this instance, and I was totally stumpted.
Then I remembered that the upgrade process would be executing all these commands under the App Pool account that was created for the site.
The AppPool was using the build in NetworkService account. And that was the problem. This account only had read permission to the web folders. The solution was to do one of two options
- Switch to a domain account that had permission to modify the web folder
- Modify the security on the folder to give the NetworkService account modify permission
Once this change was actioned, I was able to run the upgrade wizard through to successful completion.