External card folders not displaying when connected to PC

[Android Central Question]

I have an ASUS P0008 tablet, the OS is Android 7.0. The external micro-sd card is 128GB and I have verified it is that size.

I use the tablet primarily as my 'photo' album and have nearly 30,000 photographs from nearly 60 years of photographing on the card. The photos are fairly organized into multiple folders, by year since 2013.

When I connect the tablet to my Windoze 10 PC and go to the 'photos' folder, it shows up as empty though there are (currently) 129 sub folders. Perhaps a better example of how I have the photos folder organized would be beneficial.

Photos
folders by name
some further divided, but no lower than this level
folders by year
folders by month
folders by topic/subject

Other than the 'photos' folder, none of the sub folders show up. Up until roughly two months ago, they all did show up.

I have tried clearing the memory buffer/cache (a previous answer) and this helped once, but no longer has any effect.

When I want to add new folders (all are in the 'year' folder), I have been forced to copy from my PC to another folder through the USB and then move the new folders through a file management app once on the tablet. Once I have done this, the new folders do show up (in the tablet file manager) where I want them, but they are no longer visible on the PC.

An aside to this, once I have moved the folders on the tablet, next time I connect to the PC, the moved folders are still showing in the 'temp' folder on the tablet.

I have tried reducing the number of first level sub folders by using two folders, one for 'named' folders the other for 'numbered' (e.g., the 'year') folders. Once I did another cache clear, the two folders and all their sub folders are now there. How long this will last, well I am not going to take bets it is permanently fixed.

Does anyone have any idea as to why suddenly all the sub folders vanished when connected to the PC through the USB. Is there some limit to the number of folders (like in the old DOS days), a hardware/software issue between the tablet/PC and Android.

Many thanks for any help/advice.

 

[B. Diddy]

Welcome to Android Central! First -- if you haven't done so already, back up all of those photos somewhere safe. SD cards are inherently less reliable than onboard memory or physical hard drives, and can fail without warning. Unmount the card (in Settings>Storage), remove the card, and insert it into your PC. Then copy all of the photos to your hard drive. I would also recommend uploading your photos to your Google Photos in the cloud -- if you choose the High Quality (which is slightly compressed), you get unlimited storage: https://support.google.com/photos/answer/6193313?co=GENIE.Platform=Android&hl=en.

Next -- when the card is in the tablet and the tablet is connected to the PC via USB, look carefully at the device list. When you click the tablet, do you see Internal Storage and SD card listed separately?