2.80 (sub 45), 798d2cadc307, 2019-03-04 00:30
IDK how to reproduce, I just working a lot with shader, trying to achieve certain result.
But here is the file.
As I found: error is inside material: it remains if i append material.
May be it is similar issue, that was with value-node stucking.
And the bug is «viral»: look 3rd video. It seems, it expands to all nodes with color, not only multiply
Even after deleting bugged material and data, there is strange behaviour… 4th video and 2nd file