Printer won't print pdf - 'printing - can't open /private/var/spool/cups/tmp'

I recently upgraded my mac to catalina which didn't work out for me so I downgraded back to Mojave using time machine.

Since then I cannot print pdfs like I usually would as it comes up saying:

printing - can't open /private/var/spool/cups/tmp

I can however still print from the same files if I select print as image in the advance print settings.

I am non techy, please can someone help so I can print as normal? 

I have re-installed both prniters many times and they are fine with other laptops, it just seems to be these pdfs.

many thanks