Report a bug

Write what went wrong. You do not need to know why — "I put a splitter on a corner and my iron vanished" is a perfect report.

Click !? in the game's OPERATOR LOG panel — it copies this for you. Then paste here.

What happens to it: the report is sent to textorio.eu and saved as a text file that only I can read. Nothing is published, nothing is shared, and there are no trackers or third parties involved. Leave the name field empty and the report is anonymous — I keep a one-way hash of your address purely to stop floods, never a log of who visited.

The game will not start, or it crashed on launch
Every error is written to a file on your machine, whether or not the game is still open. Paste this into the Windows Explorer address bar, or press Win+R and enter it: 
%APPDATA%\Textorio\textorio-errors.log
It is plain text, newest errors at the bottom. Copy the last twenty lines or so into the Diagnostics box above.
What makes a bug get fixed faster
Whether it happens again. A bug I can reproduce is usually fixed the same day; one that happened once is a mystery for weeks.

A screenshot, if it is something you can see — there is a Screenshot button in the game's Settings panel, and it saves to %APPDATA%\Textorio\screenshots\.
Prefer to post it publicly?
The Steam discussion board is the best place — other players can confirm they are seeing the same thing, which tells me how widespread it is. The buttons above take you straight there with your report on the clipboard.