This error occurs if you attempt to write to a shared variable that is set to read only.

Note   If you create a Shared Variable node for a variable that is set to read only, the node has an output and can write to other objects on the block diagram. The Shared Variable node is set to write.

To correct this error, right-click the Shared Variable node and select Change To Read from the shortcut menu, or configure the shared variable to allow write access.