Android Studio 3.1 layout preview does not show preview for some layouts

Question

Since today morning I started encountering this weird issue. Android Studio layout preview panel and Design view was not displaying some of my layouts which were perfectly f

Answer 1

After many failed attempts and submitting it to Android Studio bug tracker and giving it an another try. I found that it was due to a missing "+".

Sample layout to demonstrate the issue

The issue was because of a missing + in leftTextView id declaration. After changing the line (line no. 18)

android:id="@id/leftTextView"

to

android:id="@+id/leftTextView"

Android Studio layout preview panel started displaying the layout.

Note : I always used to declare view ids (i.e., "@+id") only once in a layout file at its first occurrence(either declaration or reference) and there was no issue with layout preview or running the App till now