Hello Garima,
We found no permanent solution to this issue. It seems to be a RoboHelp bug that appears under certain conditions...
However, we've elaborated a workaround:
1. After first WebHelp compilation, I copy the output to some temporary location on my PC.
2. Compile the WebHelp for the second time.
3. Replace the empty HTML files in the Output temporary folder with the good files from the second compilation.
Sometimes, some blank files from the first and second compilation output remain blank. So, I recompile the WebHelp as many times as needed to replace all the blank files in the Output folder that is in the temporary location. Once done, I replace the Output folder from the last compilation with the Output folder that I copied to the temporary location in step 1 and which now contains all good files.
I know, the process is not convenient at all; however, it is better than nothing 
Regards,
Kate
Hi Kate,
I was also facing the same problem with the blank topics in the Webhelp output and found the solution to it. It's because of the antivirus software. One of the antivirus software's tools used to scan all newly-created files instantly, which was interfering with the Webhelp generation. Once I turned off that tool, this issue was resolved. So you can either turn off the antivirus completely or just this specific antivirus utility.
Regards,
Ritesh Pai