Links to topics at the folder level unresponsive in CHM

[GLNT1]

RoboHelp 2019 New UI

I have set up topic links to folders in my project TOC and when output to ResponsiveHTML5, the links work fine.  But, when I produce a CHM of the same TOC, two of the folders are unresponsive and do not show the topic. All of the linked topics just consist of a single JPG.  I don't see any difference in the topics such that only 2 would not display (see image).

[GLNT1]

Upon checking the two "nondisplayable" HTML files in explorer, I get this message. So, I guess this is not a RoboHelp issue. I don't remember doing anything different with these images.  

[GLNT1]

After futher troubleshooting, I found the issue.  The topics that were not showing had JPGs that had an "&" in the title.  It looks like the CHM has a problem with those, but not HTML5.

[Peter Grainge]

The CHM compiler was last updated by Microsoft in 2004. In those days only alphanumeric characters and a few others such as underscores were permitted, so no surprise with that. Generally I stick with those characters as it is always safer.

Well done on the detective work.

[Peter Grainge · Accepted solution]

I have since learned that the & in the file name causing the problem is a bug that will be fixed in an update. Nonetheless, I still recommend sticking with alphnumeric characters, hyphens and underscores in file names generally.