Okay, some observations:
- MultiBit Classic 5.16 is more than two years old.
- The transaction you mentioned doesn't appear on either blockexplorer.com, blocktrail.com or blockchain.info. It seems that they didn't get propagated in the network.
The Bitcoin transaction market has evolved in the past two years and due to a higher demand, the transaction fees have become more competitive. I would guess that your old version of MultiBit wouldn't have a good estimation for fees. Therefore, it seems likely that your transactions didn't fulfill the 'minimum relay fee' criterion and didn't get relayed by the peers that did see them.
I found this FAQ that addresses specifically your issue: I sent bitcoin from MultiBit Classic but they are stuck., which provides a similar explanation as one of the most likely reasons.
- Update your software to a more current version to mitigate this issue in the future.
- As suggested in the above FAQ: "You can remove the transaction that never propagated by doing a
Tools | Reset Block chain and Transactions."
As always, if you don't have a backup of your wallet, you should create one, especially before changing things about your Bitcoin software, but also in general.