[Plugin: WP Photo Album Plus] The album index table needs to be rebuilt

Since I update the plugin to the latest version (6.1.8), I get two massages:
“The photo index table needs to be rebuilt. Please run Photo Albums -> Settings admin page Table VIII-A9”
“The album index table needs to be rebuilt. Please run Photo Albums -> Settings admin page Table VIII-A8”

So I went to that table, under A the two rows 8 and 9 have Do it – !start and a required status, so I pressed start, one at a time, waited till it changed to Ready status and Do it- 0. But when I refresh, nothing happens, the two massages still there and that two rows still have required status.
But now I get two more green massages – “Rebuilding the Photo index needs completion. See Table VIII”, they both the same.
When I go to that table, as the massages suggest, everything looks the same as it was in the beginning.

What can I do?
Thanks in advance.