cannot modify a split back end in ms/access 2013

I had a on file database ad then made the split. Now I need to modify some tables and ms/access 2013 does not allow to modify them either via the front end or, directly, in the back end (on the back end refuses to open the file due to "a security concern" and requires me to digitally sign the file, which I do not know how to do.
I went to the trust center and added the back end location as a trusted locations, but it did not help.

what shall I do? can anyone help?
João serras-pereiraAsked:
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Scott McDaniel (Microsoft Access MVP - EE MVE )Infotrakker SoftwareCommented:
You cannot modify a table linked in the FE.  You must do so directly in the BE.

Close the FE entirely (make sure EVERYONE is out of the database), then copy that BE file over to your machine. Make your changes there, then copy the updated BE back to the original location.
João serras-pereiraAuthor Commented:
Hi Scott.

thanks for the prompt answer.

I did it. Closed everything and even REBOOTED my PC to make sure that I had no tasks using the database. at no avail...

always getting the same message when I try to open the back end...

Looks like your backend database has the ".accdc" extension.  I believe that relates to the digital signature but that's about all I know on that.   My suggestion is changing file extension on the backend database to ".accdb" and repoint the frontend to the newly named backend.
Good luck

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João serras-pereiraAuthor Commented:
really thanks!!! It worked! bloody microsoft!
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