Hello,
I have the same problem and the profile is not broken. Auto-updated miranda today and my profile is in unknown format. Reverted back (yes, from Plugin updates\Backups) - all is back to normal - the same profile file opens, full of its data. The working Dbx_mdbx.dll is from 16.07.2018, ver 0.95.8.7.
Updating just a single thing breaks everything again. We need a solution for this, please!