Perhaps try this:

Is there a manual install for Visual Basic Application? (sage.com)

Just did the manual install.

It didn't work, still getting the same result.

Are there any other steps to do after installing the vba7.1?

Install Office

I installed Office and then went to Excel Trust Center and changed the macro setting to "Enable all macros".

Still the same.

Went to Word Trust Center and also changed to "Enable all macros".

No effect on Sage 300 - the macros there still not working. 

I have finally managed to get the macros working.

This is what I did:

(1) uninstalled Sage 300 and Office

(2) re-installed Sage 300 and tested the macros - not working

(3) re-installed Office and tested the macros - finally working!

and then just to confirm that Office was the solution,

(4) un-installed Office again and tested  - macros are still working!

Not sure why the macros are still working after uninstalling Office ... does anyone have an explanation?

Uninstalling office doesn't remove everything. Back when Sage wasn't installing the font they used for all of their Crystal reports (and I'm not sure if they still don't install it) all of the reports would come out in Times New Roman.

If you installed office, that would install the font, and your Crystal reports looked correct. If you then uninstalled office, your reports remained looking correct because the uninstall did not remove the font.

I don't know what it left behind but it's not a full uninstall.

Uninstalling office doesn't remove everything. Back when Sage wasn't installing the font they used for all of their Crystal reports (and I'm not sure if they still don't install it) all of the reports would come out in Times New Roman.

If you installed office, that would install the font, and your Crystal reports looked correct. If you then uninstalled office, your reports remained looking correct because the uninstall did not remove the font.

I don't know what it left behind but it's not a full uninstall.