What happened to my apps?

Start by checking storage space available. some older versions of android have a nag of accumulating useless data in some corners of the system. You may not be able to see what uses the space, but at least it will tell you if there is space or not. To help you, i need to know if there is actually any storage left or not.
This can be found in "settings -> storage"

Note: Internal storage = the onboard storage from the factory. memory is the RAM, nothing can be saved here. So if you have an EXTERNAL micro sd put in, please provide this information.

If you using a computer you need to clean your hard drive of old not used items and or install another or bigger hard drive. If it's a phone you can simply install a microsd card or a bigger one

Hi
If the machine is returning "out of storage space ", then you need to remove ether data or apps (or both) so that the machine has some storage space with which to work.
Alternatively, you can add in an SD or SDHC card or micro card, thus giving you extra storage as 4Gb is quite a small amount for processing.
Hope this is helpful, if so would you please register that with Fixya
Cheers

no but you need to chose where to save the app, so either move everything to the SD card or chose as you download

See if this helps: Storage Powered by Kayako Help Desk Software

It's from the Nextbook site and talks about the caches you mention.

You need to move app/pictures/mps or what is taking up space on the main storage to the SD-card.

As far as i know this meathod usually works with apps. First you go to settings, second you go to storage, third you go to something like apps, fourth you select an app, fifth you select move to SD card or move to internal memory depending on where you have your data saved. I hope this helps anyone with this problem, im no expert but i will try my best to help

My first suspicion would be virus. Close 2nd would be he was doing something he should not. Best option is to talk to the place you bought it from or the maker's customer service people.

Tablets have internal storage and external SD cards (optional) storage. Apps will download to the internal storage. So under Settings > Storage make sure you have space on your internal storage.