Miui Optimizations

[Ico_Sopot]

Does anybody know what MIUI optimizations mean when enabled on phone.
I was playing with some setings on my phone and I tried to disable MIUI optimizations.
My phone is Redmi Note 3 Snapdragon variant 3/32.
ROM is MIUI by XIAOMI.EU 7.5.2.0 (LHOCNDE).STABLE
Problem is , that i can not attach any file in gmail or stock e-mail application if MIUI optimization is
disabled.When i click button to attach file nothing happened , just went back to home screen of gmail app.
When MIUI optimization is enabled when I click to attach file , menu is opened to choose file and everthyng work well.
Is it a bug? Anybody else tried to disable MIUI optimizations?

 

[Ico_Sopot]

Give this a try:
Go to settings >all applications >downloaded applications and find "documents" and enable/disable it
If you couldn't find in the alphabet order then scroll till the end to find it......

Tnx , it worked!
But what is that application documents and her purpose and why have to be disabled?