If you have SciViewer active in your Fiji/ImageJ with the most recent BigStitcher update it will not allow you to work with the XML viewer and functions. However, simply uninstalling SciViewer will allow for the BigStitcher Plugin to begin to function correctly again.
If you have SciViewer active in your Fiji/ImageJ with the most recent BigStitcher update it will not allow you to work with the XML viewer and functions. However, simply uninstalling SciViewer will allow for the BigStitcher Plugin to begin to function correctly again.