[0.16.19] "Export blueprint to string" buttons don't work

[waltermundt]

To reproduce:

1. Start the game
2. Open any blueprint from character inventory.
3. Click the "export to string" button

Expected result: blueprint string GUI appears.
Actual result: nothing happens.

Log and save file attached per sticky instructions, but I'm guessing they're not particularly relevant in this case.

Edit: oh, and just to be clear, this is in vanilla, no mods loaded.

Edit 2: seems this is a subset of a bigger bug, which could be described as "blueprint GUI windows (mostly) can't open other windows" -- I also can't open a blueprint from a book, or from the blueprint library. The "import from string" dialog in the library still works though.