Sorry for the inconvenience.
Based on the error details , we suspect that you have missed to install input packages in your sample. Kindy check by installing input packages in your end. Also, ensure whether all the dependencies of DropDownList has been installed in the node modules folder. Please find the list of dependencies from the below document.
Refer to the below link for installing missing packages.
We have also ensured the working of DropDownList with latest version. Please refer to the below given sample.
If the issue persists kindly share us a video or sample to replicate the issue so that we can proceed further.