After installing GOG Galaxy and adding no man's sky and going through a 5 gb update i no longer have a save file and have to from the start.Is this a known issue,i looked through the forums but nothing similar.I really dont want to start from the beginning after going through all the play time i put into it.

It's likely because you decided to anwer no to the message where it asks you to keep the savegames during un-installing.

But you can recover old saves:
RM button on the savegame folder with your saves > Properties > Old versions. Open an old folder and re-copy your old saves.

Hope this helps,

I feel your pain. Towards the last days of the Pathfinder update (1.2) I had a pretty much unbeatable ship; a multi-tool so deadly I'd ramp up to Level 5 sentinels just to kill a walker for a good screenshot; a greenhouse where I could harvest 2 million units of crops whenever I dropped in; and more cash on hand than I could spend.

At this point, though, I'm glad that I decided to toss it away and start over after 1.3. There have been a lot of changes and it really has been fun leveling-up with the new gear.

Still lots of complaints about 1.3, including the (still) broken ship scanner, some prices that are totally nuts, and pirates that are sometimes impossible to defeat. I want my lock-on Phase Beam back!

Your post makes no sense,gog updated with no messages and after that when i loaded no mans sky there was no save file to load,rm the file?What does that mean?

The save files you think are missing are located here:

C:\Users\[USER]\AppData\Roaming\HelloGames\NMS\DefaultUser

With RM Button I mean Right Mouse Button.
Go look if your missing files are still in the DefaultUser folder (look at the date), if yes, no problem: start the game as usual. If no, do as I suggest above to solve your problem. This may not work however, it depends on the restore settings in Windows, how often restore points are created and how much GB you assign for it. If this doesn't work, I'm afraid your files are lost.

Looks like the save file is gone for good.

You could try using something to unerase the files but you'd want to install that to a drive other than the one the files are on. Minimizing writes on the drive with the saves or not writing to that drive at all would be the best thing. There are all kinds of utilies that can unerase files. You'd have to see for yourself what suits you. When you unerase the files, you want to unerase to a different drive, too.