In this case you should make sure that the libreoffice-script-provider-python package (or equivalent) is installed before trying to install AncientGreek. On Windows and Mac OS it seems that Python-UNO is installed by default, so there shouldn't be a problem with these Operation Systems. It just won't hyphenate. A document that won't hyphenate is not of publishable quality. Just ran sudo apt-get install myspell-en-gb which informed me that no files needed changing and none were updated i.e. It is installed in the latest version. Same result for libreoffice -l10n -en-gb.
Hyphenation Data Libreoffice
Hyphenation in cells and shapes was fixed a few days ago for Catalan (for example, paral·lel » paral-lel, instead of parall-lel), Hungarian (eg. asszonnyal » asz-szony-nyal instead of az-szoy-nyal) and Dutch (eg. omaatje » oma-tje instead of omaa-atje, cafeetje » café-tje instead of cafeét-je). Swedish, Norwegian and partly Dutch need only hyphenation dictionary extension to support non-standard hyphenation in LibreOffice, Greek and Dutch need also Writer and Calc/Draw (editeng) development to support the alternation after the hyphenation break. More information: bug 63711 (closed), bug 42383 (open), Hyphen library (see tests/unicode.* example for non-standard hyphenation patterns of Dutch, Greek, Norwegian and Swedish).