Android studio 3.1 XML preview not showing for some XML layouts

Question

Some layouts are shown, some just have blank, gray frame. I can\'t seem to find a correlation between XML layouts that work and those that do not, there is a mixture of use

Answer 1

I've tried pretty much everything from above and nothing worked for me. Then I've downgraded my compileSdkVersion and targetSdkVersion

---> compileSdkVersion 27

---> targetSdkVersion 27

and then

---> implementation 'com.android.support:appcompat-v7:28.0.0-alpha3' to

---> implementation 'com.android.support:appcompat-v7:27.1.1'