Background
Some Server Upgrades from version 9 to version 10 require manually removing old DevExpress assemblies. When manually uninstalling EIOBoard, the old versions of these assemblies remain. You will receive a similar error after login telling you the website cannot decide which to use.
Resolution
The best resolution is to delete the website from IIS then reinstall it with the EIOBoard Installer in Advanced Mode.
When the serve is hosting multiple sites another solution is to uninstall the following DevExpress DLLs. You will need the GAC Utility installed on your server to complete the following commands.
You will find the GAC Utility in the Microsoft SDK download available here:
https://www.microsoft.com/en-us/download/details.aspx?id=8279
The default installation path is “C:\Program Files (x86)\Microsoft SDKs\Windows\v8.1A\bin\NETFX 4.5.1 Tools\x64”.
From the command prompt, navigate to the GACUtil.exe directory and execute the following commands.
gacutil /u DevExpress.Charts.v10.2.Core gacutil /u DevExpress.Data.v10.2 gacutil /u DevExpress.PivotGrid.v10.2.Core gacutil /u DevExpress.Utils.v10.2 gacutil /u DevExpress.Web.ASPxEditors.v10.2 gacutil /u DevExpress.Web.ASPxGridView.v10.2 gacutil /u DevExpress.Web.ASPxScheduler.v10.2 gacutil /u DevExpress.Web.ASPxThemes.v10.2 gacutil /u DevExpress.Web.ASPxTreeList.v10.2 gacutil /u DevExpress.Web.v10.2 gacutil /u DevExpress.XtraCharts.v10.2 gacutil /u DevExpress.XtraPivotGrid.v10.2 gacutil /u DevExpress.XtraPrinting.v10.2 gacutil /u DevExpress.XtraReports.v10.2 gacutil /u DevExpress.XtraReports.v10.2.Web gacutil /u DevExpress.XtraRichEdit.v10.2 gacutil /u DevExpress.XtraScheduler.v10.2 gacutil /u DevExpress.XtraScheduler.v10.2.Core