Out of memory issue when importing .txt into PDF.

When i try and import a .txt file into a PDF (something I've always been able to do fine) I get an error telling me my computer is Out of memory. The file does not get imported.

I have tried

1. Repair of installed software
2. uninstall - reboot, install - reboot
3. uninstall, clean wipe, reboot and reinstall.
4. increase Page File size
5. obviously the machine has been restarted
6. Compatibility troubleshooting of windows 10, (i ran in win 8 and 7 mode)
7. run as administrator

Has anybody got any other options, because it seems Adobe themselves are not willing to help (I can't find any contact details!)