OK so its Photoshop, not LR giving you the error on save?
Check that you have Backwards compatibility checked in General Preferences for TIFF.
Can't hurt to rebuild the PS preferences either. Press and hold Alt+Control+Shift (Windows) or Option+Command+Shift (Mac OS) immediately after launching Photoshop.
Thanks for your help Andrew
Still no luck, I'm afraid. How can I check for backwards compatibility?
Photoshop -> Preferences -> General... -> File Handling?
Also, on trying to rebuild the PS preferences will you receive any sort of confirmation that this has been completed?