Then I stopped generating of the report and pushed Cancel button several times. It took some time and then GenoPro crashed (the red error message in report log was shown for so short time that there was no chance to read it.).

The good news is an incomplete cache has no effect on the rest of the report.  The worse thing you will get is a performance loss on the next report upload, as the cache is no longer fully working.  After generating your next report, everything will be back to normal, and the cache will work as before to speed up uploading reports.

The crash you got is because you forced the termination of the report generator while generating file toc_individuals.htm.  Generating this file is quite slow and you have to wait until the page has been completed.  If you had clicked on the Cancel button only once, and waited a bit longer, you would have had returned to GenoPro as normal.