Smart object won't open in Illustrator after upgrading from 2017 to 2018

[LucyF818]

I updated both Photoshop and Illustrator this morning from CC 2017 to CC 2018 and now when I double click on my illustrator smart objects in photoshop instead of launching Illustrator as normal I get an error message saying 'Could not edit original smart object because the application which created the smart object could not be launched'.

Does anyone know how to re-associate my smart objects to the new version of Illustrator?

(I'm internally panicking. Please help! So much work will be lost if my smart objects are permanently broken. It's as bad as opening up a .psd and finding that all the layers have been flattened without your consent)

[LucyF818]

Whew. Solved! I'm working on a PC and in windows explorer I found that my .ai files were not associated with any program after installing the new version of Illustrator. I right clicked on a (or any) .ai file and selected 'Always open with Adobe Illustrator 2018'. Now my smart objects in Photoshop are properly launching Illustrator again and all is well.