This worked on build 7.0.20252.16055, which I’m reverting to.
(for your convenience, although it’s not specific to this file, nor the block being used)
BlockHistoryBug.3dm (224.6 KB)
There are five blocks being flowed along a crv.
Move the crv’s control point and you get an error message for each block when history updates.
The error message changes depending on the situation, but all of them so far relate to failing to delete a layer.
Turning Update Children off and using HistoryUpdate works fine, although it’s a PITA to use and I’m reverting back to 7.0.20252.16055.