@Heirloom Bob
Does this error message appears only with this file?
Can you send other files to Topaz?
Which method do you use to send the image to Topaz? Plugin or ... "Edit in"?
Do you have full access to the appropriate folder?
Which Topaz application do you use?
Please provide a copy of your 'System Info'. This can be get from the Lightroom menu item Help > System Info. There's a copy button in the System Info dialog. Press this button and paste the info into your next forum post.
My System: Intel i7-8700K - 64GB RAM - NVidia Geforce RTX 3060 - Windows 11 Pro 26H2 -- LR-Classic 15 - Photoshop 27 - Nik Collection 9 - PureRAW 6 - Topaz Photo AI