Storage Analyzer needs permission to read or write to removable storage. You will need to manually provide this permission. Once done, the application will have write access permanently for this storage device. (You will need to do this again if you change the storage device). After this screen, you will be presented with a screen similar to the following:
Open the right menu:
Ensure the removable storage is shown. If there is an option similar to "Show SD Card", select it. If the option is "Hide SD Card", or the message relates to Internal Storage, leave it:
From the left menu, select the removable storage. It may be named SD Card or something similar, or have the serial number of the storage device.
Select the storage device. Note that you should provide access to the entire storage device (not the individual file or folder being modified).
This will provide the required access required for this and future sessions.