i am looking at http://bugzilla.lyx.org/show_bug.cgi?id=3293
and found that commenting out the 'if' on line 260 in insetvspace.C: - if (lex.isOK()) + //if (lex.isOK()) vspace = VSpace(vsp);solves the bug since lex.isOK() seems to return false even when things are ok.
perhaps someone who knows this lyxlex stuff (georg?) can have a look at it? thanks!