I get a block of purple stripes on my jpeg export

This is very likely a problem with the driver for your GPU card. You should go to the GPU manufacturer's website and download the latest version of the driver. If this is a Nvidia GPU, make sure to choose the "Studio" driver. It is also possible that this is caused by corruption of the raw files on disk but if this happens to many images, that is somewhat unlikely. 

Can you provide details on the camera model used?

Did you use 'Denosie' before editing the files?

It would also be helpful if you would post your 'System Info'. This can be obtained from the LrC Help > System Info menu item. You can use the Copy button at top right of the System Info dialog to capture the info, then Paste same into you next forum post.