This refers to the method how the files which are to be served are stored - with or without the headers sent out before the "webpage" itself.
In the "normal" incarnations of lwip there's a utility attached to be used to generate the "filesystem", called makefsdata, that can generate the "filesystem" (fsdata.c) with or without the headers. In the generated fsdata.c, every "file" has a fsdata_file struct which describes that "file", and one of its fields is http_header_included (which, while declared as u8, is in fact a boolean value). The assert above says, that "header for this file is not included, and I don't know how to generate headers dynamically".
Quoting from httpd.c:
* By default, the server assumes that HTTP headers are already present in
* each file stored in the file system. By defining LWIP_HTTPD_DYNAMIC_HEADERS in
* lwipopts.h, this behavior can be changed such that the server inserts the
* headers automatically based on the extension of the file being served. If
* this mode is used, be careful to ensure that the file system image used
* does not already contain the header information.
*
* File system images without headers can be created using the makefsfile
* tool with the -h command line option.
I don't Cube/CubeMX so can't comment on what you can or cannot achieve by wildly clicking.
JW
