I have troubles for making ROI with SCP plugin in QGIS 3.4. I dowloaded some landsat images with the plugin and trying to create ROI. To do it, I made a Bandset with DOS1 atmospheric correction, created a training file for making the ROI and display a 4-3-2 images with Landsat 7 corrected images. When I draw my polygon for ROI there's nothing anormal, but when I want to save those ROI, I get an error with those two messages :
Error : Error calculating signature. Possibly ROI is too small
Information : Data projections do not match. Reproject data to the same projection
My ROI aren't too small and all the bands and the training files are in the same projection so I don't know what's happening.