Problems logging into iTunes App Store

[otetzone]

For the last couple of days I'm having trouble with iTunes App Store on both of my machines. While HS Macbook (iTunes v12.6) will no longer update any apps, the Mavericks machine wouldn't sign me into iTunes App Store giving me first error -9836 and then error -50. iTunes v11.4.
Is there anything that could be done about it? I browsed the internet and found no solution whatsoever.
I think it's something about the certificates but I'm not sure. Any help or hint or workaround would be highly appreciated.
Thank you.

upd. Just in case I tried to reinstall from the recovery partition and it stated the download no longer available.

 

[satchmo]

I’m running into the exact same issues in Snow Leopard.

It seems to be related to specifically the Store portion of iTunes. This just happened a few weeks ago so I’m wondering if it’s something Apple updated on their end that has resulted in incompatibility with older OS’s.

 

[Ericplan]

I fixed this last week on iTunes 11.4 on Snow Leopard with the solution found in this topic https://forums.macrumors.com/thread...-of-os-x.2281326/?post=29569088#post-29569088