Can't download anything while SD card in phone

[captainmorgansrevenge]

Hi. I have a specific problem and I hope someone can help me. I have an android phone, no brand, it says Android 5.1 if that helps.
My phone stopped being able to download photos from apps recently. It can sometimes download apps, sometimes not, but photos from e.g. Facebook or Imgur, it says 'something went wrong' or 'download failed'. However, the moment I unmount my SD card, it works normally.
So I assumed it's some file corrupting it, I plugged it into a pc and deleted all files not needed, of the SD and phone storage. Suddenly it worked. It's been 5 days, it's mysteriously not working again, except this time it won't let me copy anything to the SD card while plugged into a pc as external storage, and there are no rogue files to delete.
How come it worked for 5 days and now doesn't work again? It seems the SD card is the problem, since everything's okay as soon as I unmount it. What the hell?

 

[webworkings]

There has to be a brand. I mean all phones are made by some company. The brand will often show when you start the phone.

I would try checking the device for viruses, malware, spyware, bad apps, etc. That can cause this issue. If you deleted anything that was needed by the app/virus/etc. then it may have taken a while for the info to get back on the device, or enough of it to cause the problem again. Scan the phone for all of the things mentioned.

Also, try checking your system for any apps installed (other than the ones that came with the phone) that were not installed by you. Happens all the time, you install one app, and it installs others.