I had problems with apps crashing and files getting corrupted, which seemed to get better when I put in a different (actually much smaller 4GB) micro SD memory card. I suspect the previous micro SD card (128GB) was a fake product which caused problems. So perhaps try a different memory card and see if that makes a difference - even a small cheap (but not fake !) card might make difference, as apps and the operating system may use it and have problems if it is faulty. ... View more