I tried #9900# and I got that MMI message.
I realised I had not put the *#9900# * so i did it again and the option came up pressed it and now I have a lot more storage memory though I am apparently using a lot anyway.
Phone seemed slow to bring this up at first, so I restarted. I have AVG Cleaner (free version) and I was using that to keep on top of the storage problem. It now says I am in the green. I deleted 17mbs worth right away it seems to pile up quicker now.
I was able to update some of my apps ...I had got rid of everything but what i use every single day. There are a lot of Samsung apps I am not sure if they are needed or not that I would like to delete.
Because I made a mistake and got the same error message some of you are getting, are you 100% sure you put in the star? I didn't but when I did it worked.
Worth trying a couple of times.
I decided to google it as well and there were a lot of selections you guys that are having that problem might like to try them out and see what works then post back here on what worked.
I got told when I tried to post the link that I had to have ten posts first..... so just put http etc etc in front of the below links
google.com/search?q=Connection+problem+or+invalid+MMI+code&ie=utf-8&oe=utf-8
For those that need visual clues i also found this link with some graphical shots to show you what to do.
scarletfire.co.uk/fix-android-insufficient-storage-available-problem/
From the comments on that link above, some people mention that they have this storage problem because of their google account.
I have been able to update apps i have not been able to update for a good long while. I was going to buy an upgrade, but I will hold off now cos this works perfectly well otherwise.... well I do have some phone issues but maybe they will go away now? Perhaps the storage problem was causing the sound to not work when people rang me now and again? The fact wifi and screen orientation turns itself off without asking? The fact that it freezes and all the wrong times? Does any of that happen to you guys with the storage problem?
Tina