I don't understand Russian, so I answer in English.
The reason why the file cannot be read seems to be that the object name contains certain characters. We will consider fixing this problem in the future update.
And, I provide a workaround using a text editor now. I am using "Notepad++" here, but I think you can do the same thing with any other editor.
* Open the .mqo file in a text editor.
* Confirm the encoding of the file. You should see "Windows-1251" in the lower right corner in the notepad++.
* Convert the encoding to utf-8. In notepad++, call the "Encoding > Convert to UTF-8" menu.
* Confirm that "Codepage 1251" is written in the third line, and rewrite it to "CodePage utf-8".
* Save the file, and open it in the Metasequoia.
2021-10-19 17:13
Sorry, there was one mistake.
Please rewrite the third line to "Codepage utf8". Not utf-8 but utf8.
2021-10-19 21:35