After changing Build Tool Version on the pop screen
26.0.1 changed into 26.0.3 // else selected the highest available version
then click OK started working for me...
(or)
Simply Restart Andoid Studio File->Invalidate Caches and restart
与恶龙缠斗过久,自身亦成为恶龙；凝视深渊过久,深渊将回以凝视…
