Add-in Ribbon won't stay in Excel

Hi,

I wonder if anybody had similar experience and any solution to this.

Normally the S&OP / IBP ribbon will appear in Excel at launch, on occasion when Excel disabled the Add-in, user can enable it back manually with File / Options / Add-in / Manage - COM Add-in.

For a small number of our users, every time when they open up Excel, the S&OP Add-in ribbon is disabled by default, so they have to go through the path every time to enable it.

Is there a way to make sure the S&OP Add-in button stays enabled at launch of Excel?

Thank you.

Yee Ann