Phone cannot access main memory, looks for absent SD card

[ARinMD]

I have a ZTE Blade A452 (cheap phone for prepaid cellular while I'm in Germany), and it has an issue with accessing the memory. The phone will not display any photos, though I can take them and even access them with another app I installed (FX). Ditto for downloaded files of any sort. I can still take photos, but Gallery is empty, zero files.

Here's what I've tried:
-Stopping Gallery, clearing cache, restarting. Nothing.
-Stopping Media Storage, clearing cache, restarting. Nothing.
-Downloading a couple different media rescanning apps. Nothing.
-Tried to find "nomedia" file. Nothing.
-Connected it to my computer -- no files found. When I switch to USB mode, it shows "SDXC" with no files, but I do NOT have an SD card installed. I only have the base memory of 8GB. Accessing the storage in settings, it shows that there are files there, including media files. There is another storage listing at the bottom, presumably for an SD card, but it sits there like it's still scanning forever (dots...).
-I looked through everything and cannot find a setting to force the phone to look at the phone's memory instead of the missing SD card, which I have never installed.

I'm at my wits end here because I have tried at least a half dozen different "solutions" but no joy. I do not know why the phone keeps looking for an SD card or how to force it to stop. Any ideas?

It's running Android 5.1. Recently updated. Firmware is 1.0. Phone works otherwise -- texting, calls, WhatsApp, maps, Gmail, etc. Phone has two SIM slots, only one is occupied by Vodafone SIM.

 

[svim]

Try going back into your Application manager, open up the Gallery app in the list. Now tap the 'Force stop' button and then the 'Clear data' button. When you did 'Clear cache' that just wiped the app's cache, by clearing the data that removes the settings and configuration of the Gallery app (and no it does not wipe any photos). It sounds like perhaps a setting in the Gallery app was inadvertently set to not detect the DCIM folder. By doing 'Clear data' that returns the app to its original, unused state, the same as the first time you used it. Now go back and open up the Gallery app and see it there's an improvement. From your description it's not a matter of your phone not being able to see the main memory (if that were the case your phone couldn't run as it would not be able to access the operating system), it sounds like perhaps a setting in the Gallery app was set to not detect the DCIM folder.

 

[ARinMD]

I already tried that. It's not isolated to the Gallery app -- it's the entire phone. I was looking at it tonight, and at one point, the phone said that I needed to "disable USB storage" and try again (don't remember exactly what I was doing). In the ZTE Cares app that came with the phone, it actually says "None" for both Total Storage and External Storage on the "Other information" screen!

My WhatsApp does not see the entire Contacts list that I have, only a couple people who I think installed the app and sent out messages to their contact lists, including me. However, when I hit the button to enter a contact from WhatsApp, I can create a new listing -- it just never appears in the WhatsApp list (I can call or text them through the regular phone and SMS apps, though).

 

[ARinMD]

When I go into Storage in Settings, both the SD card and USB mount are greyed out and can't be selected. I wonder if I could connect to either one of those if I could reset where it looks for external memory and then remove it to restore the system memory?