After update 8.7.0 seven admin theme can't find icons I updated my Drupal 8.6.15 > 8.7.0 After updated page not found error keep coming. (I attached photo below)

It happens only in Admin theme, when I change admin theme to default theme, errors are gone. I installed a new test site with 8.7.0. but no error has happened. I tried to change core folder, theme folder. and icon files are still in the same location. I'm really confusing now. I tried to revert older version of drupal core. when it happened errors are gone but my drupal has problem. (DB is still has information of newer version I guess..) I think path of icon is wrong. error shows me wrong location.

I guess nothing wrong with new core version. but something has happened with my previous settings which I never know. anyone can help me?
Suggestions

I see that you are new to the community, so welcome. Here are some suggestions:


Make sure you performed the updates correctly (preferably using composer)


I see that you've already cleared cache (:

See if the files are actually there in your file system.


If you're not getting this problem on your dev env and only getting it on your server, see if the files are getting uploaded properly.
I had a similar problem and the reason was because of a .gitignore entry which was ignoring the icon files, so they were not getting committed and as a result, they were not being uploaded to the server.

If the SVG files exist on your server, see if you can access them by typing an absolute URL to those files


If not, then maybe there's something in your .htaccess or in your server config which is preventing you from seeing SVG files.



If all of the above don't work, please post a comment and I'm sure me / someone else will surely help.