A number of posts suggest that the following error in Figure 1 will appear if an SPWeb.Author has been previously assigned to the SharePoint Web, but has since been deleted:
This can also happen if you’ve converted a classic mode Web Application to claims-based and you were using Reporting Services in Integrated Mode before the transition. A number of posts state that the Author field must be set on all Webs in all site collections in all SharePoint Web Applications to avoid this error. I believe this is true for any Site Collection where Reporting Services integration has been deployed. You can use SharePoint Manager to check the value of the Author property in each Web in SharePoint 2007 or 2010. There is a version of SharePoint Manager for SharePoint 2007 and SharePoint 2010 on CodePlex. You can also use the Get-SPWeb PowerShell commandlet to get each Web and then check the Author property. When converting from classic-mode to a claims-based Web Application, you must also make sure that the author field is using a valid login ID. The internal claims format for a SAML-token based user account contains the prefix i:0.w| (e.g., i:0.w|contoso\user01). A user account of contoso\user01 in a claims-aware application is not a valid user account and if this is set as the value of the Author property on a Web, SharePoint will throw the User cannot be found exception. You can also use the SHAREPOINT\System account. This format is valid in classic and claims-mode Webs. You might also need to delete and replace all rdl (report) and rsds (data connection) files after the conversion from classic to claims mode and after all of the Author properties have valid value. For example, to replace a rdl file, follow these instructions:
- Navigate to the Reports library containing the reports that are throwing the User not found error.
- Download a copy of the report (.rdl) file. You can do this by hovering over the item in the SharePoint library and from the context menu, click Send To and then click Download a Copy.
- Delete the rdl file from the SharePoint library
- Upload the file that you downloaded in the first step.
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