My site started life as a DNN 4.9 many moons ago and is currently sitting at 8.0.4 working fine. I've done a trial upgrade to 9.1.1 and my changes in HTML module are not saved. I've stepped through the HTML module Edit control and the problem seems to be that ViewState["_currentWorkflowType"] is always null during the OnSaveClick event. I can see that its set correctly during load of the edit screen, but then on the postback its gone.
This is related to analytics http module, if you set the config as prepend script into body element, it will cause the control index changed then viewstate becomes invalid after postback, so that all viewstate will lost. clarify reproduce steps as below:
1. install 9.2.0 latest build;
2. config to enable google analytics( you can just copy
into your portal home directory(portals\0 folder) to enable it);
3. edit SiteAnalytics.config under website root folder with below 2 changes:
change ElementId to Body;
change InjectTop to True;
4. enter edit mode of home page, edit one of the html module, make changes in html editor and save it.
the content will update.
page just refresh but content won't changed.