hey, recently updated to limesurvey3.22.6+200219, we had 2-3 months older version.
all seems fine except from one survey which is embeded on another site via iframe. all was good before the upgrade.
now on theme options we cant see the ajaxmode option, which in advanced options is set to "ajaxmode":"off". we cant change that from GUI. this happens for all themes, core and also custom ones.
if the survey is set to show all questions in one page, it works. if is set to group by group, it gives:

400: Bad Request
The CSRF token could not be verified.
The request could not be understood by the server due to malformed syntax.Please do not repeat the request without modifications.
If you think this is a server error, please contact admin.

the survey is public and active, you can tsti it here: dev.stinpriza.org/priza/test-prorata-iframe/

priza wrote: now on theme options we cant see the ajaxmode option, which in advanced options is set to "ajaxmode":"off". we cant change that from GUI. this happens for all themes, core and also custom ones.

The AJAX-Mode was removed. So that is no bug, that you no longer see an option for AJAXmode anywhere.

The issue around CSRF is not directly related to AJAX.

hello,
do you know why and in which version it was removed?
previously we had 3.18.0 (sep 2019) in which it worked. maybe ajax exists in lime v4?

Ajaxmode is removed everywhere. LS3 and LS4.
It was removed because it was the root cause for many issues. The mode broke many questiontypes. So the first thing on every new project was to deactivate the AJAXmode.

is there an alternative form embeded surveys with multiple pages?

The AJAXmode had nothing do to with embedding a survey into a website.

LimeSurvey never offered a embedding via a javascript. The common method to embed a survey is an IFRAME. LimeSurvey has some security settings around IFRAME.
www.limesurvey.org/manual/Global_settings#Security