Seamonkey dropping inserted images; Alternatives?

Have used Seamonkey for years to build several simple web sites using Composer on earlier versions of openSuse up to 13.2. Moved to 42.1 and can’t get inserted images to stay on the page. AFAIK I’m applying the same process as before: start Composer with an older page (containing a table); insert one image per cell with relative reference to adjacent directory; adjust permissions to 744 (for SSI); upload images and the web page.

Header and Footer are inserted by SSI, but only some images appear when viewing the main page on the server from a local browser (FF 42).

Going back to Seamonkey to check, I open the image menu (double click on the image). Looks fine, but if I select the image again from the local machine, when I click OK the image in the open working document is replaced with a blank frame and an icon for a broken image. Looking at the images in Gwenview and GIMP reveals no problems.
Opened the web page local file in libreOffice. Looks a bit odd. Switched to ‘View/HTML Source’ OK, but the View menu has greyed out the Print and Web options–stuck in source. That’s not being easy for me.

Can you see what I’m missing? A thread from last April discussed other web editors, but that was before 42.1.