Please help with the strangest problem I have come across.

The following document fails (does not complete, hangs) when the 
following conditions hold:

  * ConTeXt  ver: 2015.09.01 11:10 MKIV beta  fmt: 2015.9.3  int:
    english/english
  * \mainlanguage[en] or fr
  * Font EBGaramond otf from EBGaramond-0.016.zip
    https://bitbucket.org/georgd/eb-garamond/downloads
  * Font features clig and hlig
  * Font style \it or \sl
  * Text string (among others) astro istar istra ister istor istro istur

The problem is the same with \usemodule[newotf] and without.

The problem does not occur with:

  *   ConTeXt  ver: 2015.08.30 17:07 MKIV beta  fmt: 2015.8.30 int:
    english/english.
  * \mainlanguage la or de.
  * \tf or \sc or \bd (there is no bold in the font).

The issue appears to be related to the st ligature, but only in 
conjunction with some other letters.

Can somebody else reproduce the problem. For the record, this is running 
on Windows 10 Pro 64-bit.

The problem document:

       \definefontfeature [ff:ebg][default][
                                            clig=yes,hlig=yes,  %% 1 %%
                                            ]
       \definefontfamily  [mainface][serif][ebgaramond]
                                           [features=ff:ebg]
       \setupbodyfont     [mainface]
    % \mainlanguage[la]                                        %% 2 %%
       \mainlanguage[fr]                                        %% 3 %%
    \starttext
       \it                                                      %% 4 %%
    % \tf                                                      %% 5 %%
       astro                                                    %% 6 %%
    % aStro                                                    %% 7 %%
    % asTor                                                    %% 8 %%
    \stoptext


-- 
Rik