When changing the Mip Gen Settings of a Texture 2D Array, several errors such as: Error: Corrupt texture [NewTexture2DArray]! Missing bulk data for MipIndex=0 appear in the output logs and an Ensure is hit as well.
Tested in //UE4/Release-4.26 @ CL 15973114 and this did not occur so marking as a Regression
An ensure is hit and an error saying there are corrupt textures appears
No errors appear in the output log when changing the Mip Gen Settings
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-117245 in the post.