How to import an existing mmssms.db to an Android Virtual Device?

I've downgraded from Cyanogenmod 13 (Android 6.0.1) to Android stock 5.1.1, and kept my previous mmssms.db file, but it is incompatible with older Android versions. I would like to import this database in an Android Virtual Device running Android 6.0, back it up using SMS Save & Restore, then restore the .xml file produced by that app on my device. However, when I copy my old **com.android.providers.telephony** directory in the **/data/data/** directory of the AVD, neither the Messenger app, nor SMS Backup & Restore see any message. The directory and its contents are owned by the **radio** user, belong to the radio group, and have **chmod** set to 771. How can I check what is preventing the system from accessing my database? Or how else can I retrieve my sms ?