I experienced External SD Corruption - please avoid.
C:\Windows\system32>chkdsk J: /r
The type of the file system is FAT32.
Volume Serial Number is 81AB-1500
Windows is verifying files and folders...
Removing nonvalid long folder entry from \Android\data\com.bambuna.podcastaddict\files\podcast\thumbnails...
\Android\data\com.bambuna.podcastaddict\files\podcast\thumbnails\»←ñwƒ°=.n1⌂ Invalid time stamp.
\Android\data\com.bambuna.podcastaddict\files\podcast\thumbnails\»←ñwƒ°=.n1⌂ Invalid time stamp.
\Android\data\com.bambuna.podcastaddict\files\podcast\thumbnails\»←ñwƒ°=.n1⌂ Folder has non-zero file size.
\Android\data\com.bambuna.podcastaddict\files\podcast\thumbnails\»←ñwƒ°=.n1⌂ first allocation unit is not valid. The entry will be truncated.
\Android\data\com.bambuna.podcastaddict\files\podcast\thumbnails\ªGô▓■âs;.►ÓÔ Invalid time stamp.
\Android\data\com.bambuna.podcastaddict\files\podcast\thumbnails\ªGô▓■âs;.►ÓÔ Folder has non-zero file size.
\Android\data\com.bambuna.podcastaddict\files\podcast\thumbnails\ªGô▓■âs;.►ÓÔ first allocation unit is not valid. The entry will be truncated.
Ü Invalid time stamp.una.podcastaddict\files\podcast\thumbnails\ªè,¤♂p ┴.⌂
Ü Invalid time stamp.una.podcastaddict\files\podcast\thumbnails\ªè,¤♂p ┴.⌂
Ü first allocation unit is not valid. The entry will be truncated.,¤♂p ┴.⌂
\Android\data\com.bambuna.podcastaddict\files\podcast\thumbnails\r┬eère☻╔.(µx Invalid time stamp.
\Android\data\com.bambuna.podcastaddict\files\podcast\thumbnails\r┬eère☻╔.(µx Folder has non-zero file size.
\Android\data\com.bambuna.podcastaddict\files\podcast\thumbnails\r┬eère☻╔.(µx first allocation unit is not valid. The entry will be truncated.
\Android\data\com.bambuna.podcastaddict\files\podcast\thumbnails\¿☺æ►☻p☼┬.←░­ Invalid time stamp.
\Android\data\com.bambuna.podcastaddict\files\podcast\thumbnails\¿☺æ►☻p☼┬.←░­ Folder has non-zero file size.
\Android\data\com.bambuna.podcastaddict\files\podcast\thumbnails\¿☺æ►☻p☼┬.←░­ first allocation unit is not valid. The entry will be truncated.

...
\Android\data\com.bambuna.podcastaddict\files\podcast\thumbnails\♀iI→¶├Ùp↕2ù Folder has non-zero file size.
\Android\data\com.bambuna.podcastaddict\files\podcast\thumbnails\♀iI→¶├Ùp↕2ù first allocation unit is not valid. The entry will be truncated.
Removing trailing folder entries from \Android\data\com.bambuna.podcastaddict\files\podcast\thumbnails
Unrecoverable error in folder \Android\data\com.google.android.youtube\files.
Convert folder to file (Y/N)? y
Unrecoverable error in folder \Android\data\podcast\Tech Weekly.
Convert folder to file (Y/N)? y
Unrecoverable error in folder \Android\data\podcast\Security Now.
Convert folder to file (Y/N)? y
Unrecoverable error in folder \Android\data\podcast\The Life Scientific.
Convert folder to file (Y/N)? y
Unrecoverable error in folder \Android\data\podcast\The Science Show - Full program podcast.
Convert folder to file (Y/N)? y
File and folder verification is complete.
Convert lost chains to files (Y/N)? y
99456 KB in 137 recovered files.
Windows is verifying free space...
Free space verification is complete.
Windows has made corrections to the file system.
31,259,168 KB total disk space.
7,424 KB in 219 folders.
27,883,264 KB in 5,088 files.
3,368,448 KB are available.

   32,768 bytes in each allocation unit.
  976,849 total allocation units on disk.
  105,264 allocation units available on disk.

C:\Windows\system32>