Steps to reproduce:
1. Open QA-supplied project ("AlphaToTransparencyBug_2018.zip")
2. Open Scene "Test"
3. Open Game Window

Expected: texture has no white lines surrounding it
Actual: texture has white lines surrounding it

Reproduced in: 2018.2.0a1, 2018.2.0b5, 2018.3.0a1
Not reproduced in: 2017.1.4f1, 2017.2.3f1, 2017.4.3f1, 2018.1.1f1

Note: attached two pictures:
One of 2017 ( the correctly working one )
One of 2018 ( the flawed one)

If you go to 2018.1 and go back to 2018.2 it starts working fine, reimporting the texture usually brings back the problem but it's not consistent
same with going from 2018.2 to 2018.1