Statistics issue on article page

After updating OJS from to, I have following issues with my journal:

  1. On articles “Download data is not yet available.” is shown.
  2. At the bottom of the page, “Most read articles by the same author” is not working (shows “This plugin requires at least one statistics/report plugin to be enabled”).

Looking at other topics I’ve checked the following:

  • both Usage Statistics and Recommended by Author plugins are enabled;
  • UsageStats logs are processed each day and moved to archive and there are entries inside every log;
  • metric in DB show counts for ojs::counter

I’m not sure where else to look for problems.

I’ve found following in error log:

PHP Warning: in_array() expects parameter 2 to be array, null given in /home/vetglasnik/www/lib/pkp/plugins/generic/usageStats/ on line 195 (and also 196)
PHP Warning: Invalid argument supplied for foreach() in /home/vetglasnik/www/lib/pkp/plugins/generic/usageStats/ on line 642

Any idea how to fix these?