Opening an .mdb termbase in Multiterm

As I try to open any of the glossaries created in Transit NXT and saved as .mdb files with SDL Multiterm, a question pops up:

This termbase has been created with an older version of MultiTerm and needs to be updated. This can take several minutes.

Continue opening termbases?

As I click on Yes,

an Error message pops up, saying:

There was a problem opening the termbase at C:\Users\User\Documents\SDL\SDL MultiTerm\Termbases\...mdb.

Check that this is a valid termbase and that you have permission to access it.

Continue opening termbase?

As I click on Yes, nothing happens.

I have worked in Transit NXT for several years and I have created several valuable glossaries in it before I switched to Studio 2017 last year.

Please help: How can I open them in Multiterm/Trados, or convert them to a format that can be used in Studio 2017?