No subject

may be able to fix your issue by adding the following comments in your
LaTeX documents to drive po4a for the handling of these unknown
environment.

% po4a: environment longtable {}
% po4a: separator longtable "(?:&|\\\\\\\\|\\\\hline)"

(Some explanations are in "man Locale::Po4a::TeX")

Note: I did not test this. Just send me the file which triggers this issu=
e
if you want me to have a deeper look.

The issue might also be triggered by a typo: lomgtable -> longtable

Best Regards,
--=20
Nekral