Cannot modify the Global Assembly Cache
Error Description
This error may occur when the DevExpress installer does not have access rights to the GAC or security software (antivirus or firewall) blocks access. The installation log file can contain the following information:
09.05.2019 18:36:16 *********************[Error]*********************
Cannot modify the Global Assembly Cache for DevExpress.XtraCharts.vXX.Y.Web.dll - -2147024891
*************************************************
09.05.2019 18:36:16 --- Updating the Global Assembly Cache for DevExpress.XtraCharts.vXX.Y.Web.Design.dll
09.05.2019 18:36:16 *********************[Error]*********************
Cannot modify the Global Assembly Cache for DevExpress.XtraCharts.vXX.Y.Web.Design.dll - -2147024891
*************************************************
09.05.2019 18:36:16 --- Updating the Global Assembly Cache for DevExpress.Web.ASPxGauges.vXX.Y.dll
09.05.2019 18:36:16 *********************[Error]*********************
Cannot modify the Global Assembly Cache for DevExpress.Web.ASPxGauges.vXX.Y.dll - -2147024891
Solution
Use the Microsoft .NET Framework Repair Tool to restart and re-register Windows services, modify access control lists, and clear unnecessary/missing/incorrect files and directories in the GAC folder.