user7645: Probably a stupid question, but I use XBoard with Fairy-Max or GNU Chess. In the edit game mode, or in analysis mode, it is not possible to castle under any circumstances. Is there some setting I am missing?
Edit: Here is an example:
For the position:
1.e4 e5 2.Nf3 d6 3.d4 Nf6 4.Nc3 Nc6 5.Bc4 Be7
I would like to play 6.O-O. Typing the move in returns "{White mates} 1-0". Dragging the king over two spaces returns "illegal move". Doesn't matter which engine is selected. I can castle while playing against the computer, however.


user9926: According to XBoard's manual [ref. 1]:

"...XBoard 4.2.7 and earlier... The internal move legality tester
  [had problems with] castling or en passant-capture rights."

If you're running 4.2.7 (or earlier), then a newer release should solve this problem.
Caution:  Although this is not relevant to the specifics of the question, I feel that if you are running this version, then it would be remiss of me were I not to mention that there is also a reported security risk (mid-grade: stack overflow) inherent to XBoard 4.2.7 [ref. 2, 3].

References:

https://www.gnu.org/software/xboard/manual/xboard.html#Limitations 
https://www.cvedetails.com/vulnerability-list/vendor_id-2551/product_id-4447/version_id-19153/Tim-Mann-Xboard-4.2.7.html 
http://seclists.org/fulldisclosure/2004/Mar/40 


7645: <p>Probably a stupid question, but I use XBoard with Fairy-Max or GNU Chess. In the edit game mode, or in analysis mode, it is not possible to castle under any circumstances. Is there some setting I am missing?</p>
<p>Edit: Here is an example:</p>
<p>For the position:
1.e4 e5 2.Nf3 d6 3.d4 Nf6 4.Nc3 Nc6 5.Bc4 Be7</p>
<p>I would like to play 6.O-O. Typing the move in returns &quot;{White mates} 1-0&quot;. Dragging the king over two spaces returns &quot;illegal move&quot;. Doesn't matter which engine is selected. I can castle while playing against the computer, however.</p>
<p><img src="https://i.stack.imgur.com/MDpvk.png" alt="enter image description here" /></p>
 9926: <p>According to XBoard's manual [ref. 1]:</p>

<blockquote>
  <p>"...XBoard 4.2.7 and earlier... The internal move legality tester<br>
  [<i>had problems with</i>] castling or en passant-capture rights."</p>
</blockquote>

<p>If you're running 4.2.7 (or earlier), then <a href="http://hgm.nubati.net" rel="nofollow noreferrer">a newer release</a> should solve this problem.</p>

<p><b>Caution:</b> &nbsp;Although this is <i>not</i> relevant to the specifics of the question, I feel that if you are running this version, then it would be remiss of me were I not to mention that there is also a reported security risk (mid-grade: stack overflow) inherent to XBoard 4.2.7 [ref. 2, 3].</p>

<hr>

<p><b>References:</b></p>

<ol>
<li><a href="https://www.gnu.org/software/xboard/manual/xboard.html#Limitations" rel="nofollow noreferrer">https://www.gnu.org/software/xboard/manual/xboard.html#Limitations</a> </li>
<li><a href="https://www.cvedetails.com/vulnerability-list/vendor_id-2551/product_id-4447/version_id-19153/Tim-Mann-Xboard-4.2.7.html" rel="nofollow noreferrer">https://www.cvedetails.com/vulnerability-list/vendor_id-2551/product_id-4447/version_id-19153/Tim-Mann-Xboard-4.2.7.html</a> </li>
<li><a href="http://seclists.org/fulldisclosure/2004/Mar/40" rel="nofollow noreferrer">http://seclists.org/fulldisclosure/2004/Mar/40</a> </li>
</ol>
