Illustrator ガイドラインが　実線に戻ってしまう。

Hi there,

Thanks for reaching out. I tried doing the same on my end on Windows 10 and there was no change, the preference for Guides was still set to Dot. I'd recommend resetting the preferences for Illustrator by following the steps below:

• Close Illustrator.
• Click on the Finder icon on the dock, choose Go on the top> Go To Folder.
• In the Go To Folder dialog box, type "~/Library". Click Go.
• Open the Preferences Folder > rename the Illustrator  24 Settings folder to Illustrator  24 Settings folder.old
• Under Preferences, Open Adobe folder and rename Adobe Illustrator folder to Adobe Illustrator.old
• Go back to library->open caches->rename  com.adobe.illustrator to com.adobe.illustrator.old
• Go back to library->open application support-> open adobe->rename the Illustrator  24 folder to Illustrator  24folder.old

Disclaimer: 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.  

After resetting the preferences, please try it again and let us know if it works or if you need any further assistance.

Regards

Rishabh