UI completely broken in 2.56a1 Trunk ⚠️️

I used a newly created test profile

So (browser-) UI looks with official en-US SeaMonkey 2.56a1 (NT 6.1; WOW64; rv:59.0) Gecko/20100101 Firefox/59.0 Build 20180119000058 SourceStamp=ae43fcf7b9ee449f0f0a573d10c93421dbe645bf || ID={92650c4d-4b8e-4d2a-b7eb-24ecf4f6b63a} (Default Classic Theme) on German WIN7 64bit.

May be developers should give some advice in which area and for which builds user-bugreports currently can be useful? I doubt that testing with current (WIN) trunk can yield any benefit 🤔.