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Reported issue: Symbols are not displayed in the Stencil.
We have analyzed the provided sample. The SymbolFilter and SymbolGroups of Stencil was not initialized in your sample which causes the reported issue. The SymbolFilters are the collection of SymbolFilterprovider, which is used to filter/hide the symbols using delegates. Based on the return Boolean value of the SymbolFilter delegate, the corresponding item is removed from Stencil .We have resolved the reported issue by modifying the provided sample. Please refer to the sample from the following link.
For more details about stencil,please visit our OnlineHelpDocumentation link.
Also, refer to our Dashboard sample Stencil from the following link.
Link: Dashboard->WPF->Run Local Samples-> Diagram->Getting Started->Stencil.