...
These errors occur because the NBIA Data Retriever cannot work without with a manifest file. See Creating Manifest Files for instructions on how to create a manifest file using NBIA TCIA or an API. To avoid this error, download and install the NBIA Data Retriever first, then locate a manifest file on your computer. If you have not previously installed any versions of the Downloader App or TCIA Downloader, just click a manifest file and the NBIA Data Retriever will open it correctly. If you have installed the Downloader App or TCIA Downloader before, consider removing these applications first before installing the NBIA Data Retriever. This is not mandatory but will prevent you from having to specify which application your computer should use to open the manifest file. To do so, right-click the manifest file and choose to open it with the NBIA Data Retriever.
...