Just a wild guess but maybe the installer wants the "real" bash and you have dash set up (I think ubuntu and debian do that nowadays).
That or you're missing an executable or some command returns an error that's poorly handled (since we all know proper error handling is borderline impossible in shell scripts...).
That's why I don't get the point of bash scripts: if you want something truly portable you might as well use /bin/sh and if you're willing to compromise a bit of portability for more advanced features you might as well switch to perl or python (perl is probably as likely to be installed on any un*x machine as bash).
That or you're missing an executable or some command returns an error that's poorly handled (since we all know proper error handling is borderline impossible in shell scripts...).
That's why I don't get the point of bash scripts: if you want something truly portable you might as well use /bin/sh and if you're willing to compromise a bit of portability for more advanced features you might as well switch to perl or python (perl is probably as likely to be installed on any un*x machine as bash).