Hi Tamas,Thank you for using Syncfusion products.We are not able to reproduce the reported issue at our end with SfPicker control. We suspect that there may be a conflict with assemblies. A similar issue was faced by one of our customer and cleaning and clearing the .nuget cache resolved the issue faced.Can you please close all your VisualStudio instances and clear your project bin and obj files. Also clear the packages under the below location and deploy your application.C:\Users\$UserName\.nuget\packagesPlease let us know if the faced issue with your application has been resolved or not.Regards,Paul Anderson