After Anroid 6 update Google once again hanged the storage path detection mechanism, so here is solution:
Please use this my small utility for missing mount points detection. Add mount point in the Add drive dialog. https://www.dropbox.
com/s/8upy8qhmv99rsgn/app- debug.apk?dl=0. No dangerous permissions and ads.
You will see something like this:
ExternalCacheDirs /storage/emulated/0ExternalCacheDirs /storage/3837-6538 - this is example, you will see your sd card location.
After this please add this path /storage/3837-6538 (value from sended application) to the device storage analyzer. On the main screen with Drives press + and choose Add drive. In the first line write /storage/3837-6538 (value from sended application). In the second - some label, for example SD card. Hit OK.
Hope this helps.
Feel free to write me if you need some additional help.