(svn r18298) -Document: that the dummy AI message is because 'you' don't have an AI... and how to 'solve' the issue; way too many people are ignorant

known-bugs.txt

@@ -62,6 +62,17 @@ reasons why we think that fixing them is infeasible. We might make some
 minor improvements that reduce the scope of these bugs, but we will not
 be able to completely fix them.
 
+No suitable AI can be found
+	If you have no AIs and an AI is started the so-called 'dummy' AI will
+	be loaded. This AI does nothing but writing a message on the AI debug
+	window and showing a red warning. There are basically two solutions
+	for this problem: you must change the settings so no AI is started,
+	this is done in the difficulty settings window. The other solution is
+	acquiring (downloading) some AI. The easiest way to do this is via
+	the "Check Online Content" button in the main (intro) menu or via
+	"AI Settings" -> "Select AI" -> "Check Online Content" which is also
+	accessed via the main menu.
+
 Clipping problems [FS#119]
 	In some cases sprites are not drawn as one would expect. Examples of
 	this are aircraft that might be hidden below the runway or trees that

readme.txt

@@ -176,6 +176,15 @@ If you want savegames and screenshots in the directory where the OpenTTD binary
 resides, simply have your config file in that location. But if you remove this
 config file, savegames will still be in this directory (see notes in section 4.2)
 
+OpenTTD comes without AIs, so if you want to play with AIs you have to download
+them. The easiest way is via the "Check Online Content" button in the main menu.
+You can select some AIs that you think are compatible with your playing style.
+Another way is manually downloading the AIs from the forum although then you
+need to make sure that you install all the required AI libraries too; they get
+automatically selected (and downloaded) if you get the AIs via the "Check
+Online Content". If you do not have an AI but have configured OpenTTD to start
+an AI a message will be shown that the 'dummy' AI has been started.
+
 4.1) (Required) 3rd party files:
 ---- ---------------------------