Comment 1 for bug 1719624

Installing linux-image-extra-4.11.0-1011-azure_4.11.0-1011.11_amd64.deb solves this issue, however it shouldn't be necessary from the beginning.

Plus, it adds more than needed:

ls -l /lib/modules/4.11.0-1011-azure/kernel/fs/nls/
total 1052
-rw-r--r-- 1 root root 11454 Sep 19 19:46 mac-celtic.ko
-rw-r--r-- 1 root root 10830 Sep 19 19:46 mac-centeuro.ko
-rw-r--r-- 1 root root 11454 Sep 19 19:46 mac-croatian.ko
-rw-r--r-- 1 root root 10526 Sep 19 19:46 mac-cyrillic.ko
-rw-r--r-- 1 root root 11142 Sep 19 19:46 mac-gaelic.ko
-rw-r--r-- 1 root root 10518 Sep 19 19:46 mac-greek.ko
-rw-r--r-- 1 root root 11454 Sep 19 19:46 mac-iceland.ko
-rw-r--r-- 1 root root 10830 Sep 19 19:46 mac-inuit.ko
-rw-r--r-- 1 root root 11454 Sep 19 19:46 mac-romanian.ko
-rw-r--r-- 1 root root 11758 Sep 19 19:46 mac-roman.ko
-rw-r--r-- 1 root root 11454 Sep 19 19:46 mac-turkish.ko
-rw-r--r-- 1 root root 8958 Sep 19 19:46 nls_ascii.ko
-rw-r--r-- 1 root root 10198 Sep 19 19:46 nls_cp1250.ko
-rw-r--r-- 1 root root 9894 Sep 19 19:46 nls_cp1251.ko
-rw-r--r-- 1 root root 10646 Sep 19 19:46 nls_cp1255.ko
-rw-r--r-- 1 root root 10198 Sep 19 19:46 nls_cp737.ko
-rw-r--r-- 1 root root 10198 Sep 19 19:46 nls_cp775.ko
-rw-r--r-- 1 root root 9886 Sep 19 19:46 nls_cp850.ko
-rw-r--r-- 1 root root 9886 Sep 19 19:46 nls_cp852.ko
-rw-r--r-- 1 root root 9886 Sep 19 19:46 nls_cp855.ko
-rw-r--r-- 1 root root 9574 Sep 19 19:46 nls_cp857.ko
-rw-r--r-- 1 root root 10510 Sep 19 19:46 nls_cp860.ko
-rw-r--r-- 1 root root 10822 Sep 19 19:46 nls_cp861.ko
-rw-r--r-- 1 root root 11134 Sep 19 19:46 nls_cp862.ko
-rw-r--r-- 1 root root 10822 Sep 19 19:46 nls_cp863.ko
-rw-r--r-- 1 root root 10510 Sep 19 19:46 nls_cp864.ko
-rw-r--r-- 1 root root 10822 Sep 19 19:46 nls_cp865.ko
-rw-r--r-- 1 root root 10198 Sep 19 19:46 nls_cp866.ko
-rw-r--r-- 1 root root 9886 Sep 19 19:46 nls_cp869.ko
-rw-r--r-- 1 root root 9710 Sep 19 19:46 nls_cp874.ko
-rw-r--r-- 1 root root 91798 Sep 19 19:46 nls_cp932.ko
-rw-r--r-- 1 root root 140398 Sep 19 19:46 nls_cp936.ko
-rw-r--r-- 1 root root 163470 Sep 19 19:46 nls_cp949.ko
-rw-r--r-- 1 root root 115846 Sep 19 19:46 nls_cp950.ko
-rw-r--r-- 1 root root 9542 Sep 19 19:46 nls_euc-jp.ko
-rw-r--r-- 1 root root 9590 Sep 19 19:46 nls_iso8859-13.ko
-rw-r--r-- 1 root root 9590 Sep 19 19:46 nls_iso8859-14.ko
-rw-r--r-- 1 root root 9590 Sep 19 19:46 nls_iso8859-15.ko
-rw-r--r-- 1 root root 9094 Sep 19 19:49 nls_iso8859-1.ko
-rw-r--r-- 1 root root 9582 Sep 19 19:46 nls_iso8859-2.ko
-rw-r--r-- 1 root root 9582 Sep 19 19:46 nls_iso8859-3.ko
-rw-r--r-- 1 root root 9582 Sep 19 19:46 nls_iso8859-4.ko
-rw-r--r-- 1 root root 9582 Sep 19 19:46 nls_iso8859-5.ko
-rw-r--r-- 1 root root 9278 Sep 19 19:46 nls_iso8859-6.ko
-rw-r--r-- 1 root root 9894 Sep 19 19:46 nls_iso8859-7.ko
-rw-r--r-- 1 root root 9278 Sep 19 19:46 nls_iso8859-9.ko
-rw-r--r-- 1 root root 10198 Sep 19 19:46 nls_koi8-r.ko
-rw-r--r-- 1 root root 5598 Sep 19 19:46 nls_koi8-ru.ko
-rw-r--r-- 1 root root 10198 Sep 19 19:46 nls_koi8-u.ko
-rw-r--r-- 1 root root 5518 Sep 19 19:46 nls_utf8.ko