Report generation time depends on a lot of factors, so it is very difficult to find what could be the problem in you specific case with so few information. At least remember to always specify the version of the software you are using when you ask a question in the community. Thanks.
As first step check the hardware resources of the computer where Qlik NPrinting Engine runs. The QlikView (if you are connecting to a QlikView document) desktop installed there must have enought resources to manage the source document.
Another idea: check the source document and the time that is necessary to open it and to apply a filter in the NPrinting Engine. For example, saving the .qvw with all charts minimized will decrease the opening time. Where possible move calculated fields from charts to the script because every time you apply a filter they are all recalculated so you have to wait.
From the template point of view, generation time depends a lot, for example, from the number of Levels and Pages that you are using. Every value in the level or in the page is a filter so you have to wait for the filter calculation.
These are some ideas, some starting points to analyze and improve performances. Refer also to the page Performance ‒ Qlik NPrinting.
There are also past conversations in the community about this topic.
When applicable please mark the appropriate replies as CORRECT. This will help community members and Qlik Employees know which discussions have already been addressed and have a possible known solution. Please mark threads as HELPFUL if the provided solution is helpful to the problem, but does not necessarily solve the indicated problem. You can mark multiple threads as HELPFUL if you feel additional info is useful to others.
It seems that the export from QlikView started but didn't ended.
Please check if there is a Qv.exe process blocked (for example a Qv.exe process that uses a lot of resources). In case kill it.
You could also open the Windows session 0 interactive interface and check if there are error messages or open windows there.