Just a quick note - hopefully will help people:

Invalid Block - Sender's wallet isn't synced (or you typed in the block wrong)
Not Pocketed - Receiver's wallet isn't synced

If you have a transaction that you can see on the raiblockscommunity.net website and it says 'Invalid Block' then the sender hasn't yet broadcast the block to the network - this suggests that their wallet hasn't fully synced, most likely it hasn't caught up. In this situation the solution is to wait especially if its a large web service like an exchange as they'll have hundreds of transactions to process.

If the transaction is visible but says not pocketed then it has been broadcast and now its sitting in the network waiting for your wallet to be in sync - in this situation first thing is to check whether your wallet is synced:
1) if its a web/telegram wallet then just a wait a few minutes as the admins ensure that the nodes are already synced
2) if you are using the desktop wallet:
   a) Make sure you wallet is unlocked - it won't process any transactions unless its unlocked!
   b) Check the block count the number outside the brackets and compare it to the block on raiblockscommunity.net
   c) If they are close then just wait for it to catch up
   d) If there is a big difference e.g. your block is 63 then you could try and boot strap the sync: https://bitcointalk.org/index.php?topic=1381323.msg19562825#msg19562825

RaiBlocks works in a different way to Bitcoin/clones, they work by you making a transaction and waiting for it to be mined into the blockchain, the delay is waiting for the block to be mined and then all the network confirmations - in this situation you just have to wait for your transaction. In the case of RaiBlocks the sender and then receiver have to be in sync with the network for the transaction to go through - as long as your wallet isn't synced the transaction won't go through.