Hello! If I were troubleshooting this issue on my own, I would first try installing one of the other import options more commonly used, probably the WordPress importer if you haven’t already tried. If the issue exists when trying to install that, then you might be on the right track with a permission issue on a folder. I would recommend trying to install any of the top/most popular plugins, such as the Health Check plugin or WP Super Cache, and in the event of failure, checking with your server host as to why no plugin can be installed.
The Blogger Import tool, as well as all the other import tools under the Tools > Import menu, are actually plugins. In looking up the one for Blogger: https://www.ads-software.com/plugins/blogger-importer/ this plugin hasn’t been tested in a long time and was last updated over 2 years ago. It might no longer work, especially with the latest version of WP. There might be another Blogger Import plugin you can try, by searching the Plugins repository on this site. Here is a URL based on a search I ran: https://www.ads-software.com/plugins/search/blogger+import/ Hope this helps!
