impossible to export a presentation as video

Hello

I am using a LR6, and I have a problem when I try to export presentations as videos: the process starts, but it never ends!

Exporting the presentations as jpeg or tiff works, but notr as videos.

Is there someone who faced that problem with LR6?

Is there a solution?

I tried with 2 photos only, and also in that case the export does not work (it starts but it never ends)

My pc has the following characteristics:

RAM 8,00GB (7,86 GB utilizz)

Processor Intel (R) Core (TM) i5-6200U CPU@2,30GHz

Thank you for your help, and sorry if my English is not the best!