impossible to update macbook pro 13" mid 2012 from sierra 10.12.6

[misterborne]

Hi guys !

I have been struggling for month now to update my macbook pro 13" mid 2012 to a newer OS.
It is so annoying not to be able to download many apps just because of that, so it would be great if you could help me on that case.
I don't know if it could be one reason of the problem but i changed the hard drive to a SSD one removing the DVD-ROM, and changed the Ram memory.
I tried to update to many other macOS version but non of them is accepted and working at the end, even the 10.13.2...
I tried manually downloading the different macOS because i don't have any update possible from the Appstore.
Thank you so much if you can help me on that !

 

[casperes1996]

What error do you get when you try and install it? Have you done the change in time and date?

 

[misterborne]

Sorry its in French but for Catalina update it says not allowed and for 10.13.2 it says i need update 10.13...
I don't see what you mean by changing time and date ...
Thanks

 

[casperes1996]

Sorry its in French but for Catalina update it says not allowed and for 10.13.2 it says i need update 10.13...
I don't see what you mean by changing time and date ...
Thanks

When installing an older version of macOS, its certificate is often expired, so to allow its security certificate to be validated a common trick is to set back time and date on the machine to a bit after the release of the version one is installing