I've created a custom report with dimensions:
Event Category, Event Label, Page Title
And want to see this metrics:
Total Events
Pageviews
Avg. Time on Page
Also, I applied a filter by event category.
I see my report with some values in Total Events column, but Pageviews and Avg. Time on Page are always zero. What is the problem?
Your problem is occuring due to the custom report you have generated.
Events by definition are not page views. This means that an Event dimension (category, action, label) cant have page view metrics such as pageviews or average time on page, because that information does not relate to the specific event.
One way to product the report you might want is to create a segment for sessions which contain the event you are interested in, then create a Custom Report with the dimension pages, total event, pageviews, and time on page.
Update:
Understanding what you are trying to achieve, you will need to do two reports, and merge them on pagePath (assuming there is only one video per page).
Report 1: Event Category, Event Label, Page Path, Total Events.
Event Category Event Label Page Path Total Events
Video Id1 /video1 2
Video Id2 /video2 3
Report 2: Page Path, Page Views, Time on Page
Report two requires a segment: Sessions that contain Event Category == VideoView (assumed category).
Page Path, Page View, Average Time on Page.
Page Path Page views Average Time on page
/video1 5 0:42
/video1 10 0:16
The final merged dataset would look like
Event Category Event Label Page Path Total Events Page views Average Time on page
Video Id1 /video1 2 5 0:42
Video Id2 /video2 3 10 0:16