Hi @david,
Today I went into settings and clicked “Resync Blockchain” since it seemed like I was stuck.
Since then, it has got to “Status 2/4 Downloading State” gone all the way to 100% then resets to 0% and starts again up to 100% and keeps looping. It never gets past this step and has been doing this for the past 9 hours.
Looks like I broke it. 
Is there a simple fix for this?
I have rebooted the machine 3 times to no avail.
I believe this is the solution:
Delete %userprofile%/.GrinPP/MAINNET/NODE and let it fully sync BEFORE logging in.
OK, giving that a try right now
Probably just deleting %userprofile%/.GrinPP/MAINNET/NODE/TXHASHSET and %userprofile%/.GrinPP/MAINNET/NODE/DB/PEERS would’ve been enough, and would avoid resyncing headers. But Neo’s solution should hopefully work.
There is an underlying issue though that was introduced in a recent release. I’m yet to track down the exact cause, but it appears if you start syncing from a peer and they disconnect, your txhashset (the ‘state’ referred to in step 2) gets locked, causing later attempts to fail as well. I’m investigating the issue and will create a new release once I find the cause.
Thanks @Neo-Geo, that worked for me.
@david, I wonder if the fact that I was logged in to the wallet when I resynched the blockchain had something to do with it?
I think I found the issue, and am building a new release now. Thanks for reporting the problem.
This is fixed in v0.7.5