A blank window appears while opening a file After Illustrator CC2020 Update on macOS Mojave

Hi there,

Thanks for reaching out.
I'd recommend you to reset the preferences of Illustrator. You may follow the steps below:

• Close all Adobe applications. 
• Go to locations 
• ~/Library/Caches 
• ~/Library/Application Support/Adobe 
• ~/Library/Preferences 
• Rename  Adobe Illustrator, com.adobe.illustrator and Adobe Illustrator 24 Settings folders to   Adobe Illustrator.old, com.adobe.illustrator.old and Adobe Illustrator 24 Settings.old 
• Launch Illustrator from the Creative Cloud. 

Please note that resetting preferences will remove all the custom settings and Illustrator will launch with default settings. This way all your old settings will be saved in .old folders and Illustrator will recreate new folders with default settings. 

Let us know if it works out.

Regards,

Ashutosh

Let me move this to the Illustrator forum for you, where you are more likely to receive an answer to your question.

Note that the Community Help forum is for help in how to use the Adobe Communities. Product questions should be posted in the associated product community.