error/moodle/cannotsavemd5file
From MoodleDocs
During installation of new language pack.
Probably Moodle can not create a directory *moodledata*/lang/XX_utf8 (where XX is a code of the country eg. US, UK, PL, SK) due to lack of permission (*moodledata* and lang should have write permissions) and/or php safe_mode is turned on.
To correct that:
- try to change write permissions to these directories - try to turn off safe_mode (or if it is a hosted environment ask your admin to do so) - create XX_utf8 directory on your own
And try to install language pack once again.
