I am experiencing a similar problem to Byrdye with 'phantom' broken links.
I have a project that has been running for several years, with several hundred topic pages in it.
One particular page has 15 links to other topics. 10 of these links work fine.
All links from other topics to this page work fine.
The broken links report shows 5 broken links, all going to blank topic titles. The link checker shows 5 red topics that cannot be viewed. Using the link checker and code, I worked out which links to topics are broken.
The 5 links that are broken, link to the correct pages when the topic page is viewed in Internet Explorer, but do not appear when the file is compiled into a .chm file.
I have tried right-clicking and editing each link, and right-clicking and deleting, then dragging the relevant topic to the link. They remain broken with both methods.
I tried 'restore' from the broken links dialog box - I navigated to the correct file, but it does not work.
I have checked that the file name and topic titles are the same for the 5 topics in their properties. I have checked the .hhp file, each of the topics in question has the correct file path, file name and only appears once in the the .hhp.
I have deleted the .cpd and rebuilt it.
I have deleted the page with broken links and rewritten it by duplicating a 'good' page in the same folder and re-entering the text. The same 5 links come up as broken when I try to make them.
If we call the topic with broken links A, and the ones it cannot seem to link to correctly B, C, D, E & F:
A cannot link to B, C, D, E or F.
B cannot link back to A, but can link to C, D, E & F.
C, D, E & F can link successfully back to A.
B, C, D, E & F can link successfully to eachother.
A, B, C, D, E & F can all link successfully to other files within the project.
I am fairly new to Robohelp, so please forgive me if there is something basic I have not checked. My feeling is that it is going to be something wrong with one of the files associated with compiling chm files, rather than the topics themselves, but I am not sure what else to try.
Sometimes, creating an entirely new layout fixes these types of problems. Can't hurt...
Thanks for the tip ... but creating a new layout did not fix the problem. I also tried exporting an unversioned copy and creating a new layout in case the versioning software was causing an issue, but no go.
I have resolved broken links in question by moving the file up one level. It appears that the error occurs when linking between two files at a certain depth in the file path. I'm not really sure why Robohelp referred to the topics as missing blank topics.
I was linking:
Moving file A into folder5 level resolved the problem.