[SOLVED] problem with okular

I use okular on slackware64-current in plasma 5.
It is impossible to see postscript document: I see error messages:

**** Unable to open the initial device, quitting.
(libspectre) ghostscript reports: fatal internal error -100org.kde.okular.generators.spectre: Generated image does not match wanted size: [0x0] vs requested [1192x1542]
QImage::scaled: Image is a null image