Below you find a non-exhaustive list of known issues, which you should be aware of while using the current version of the software. Most of these issues are not Raiden specific, but rather apply to all blockchain applications.
Compromised user system: If the system of the user is compromised and accessed by an attacker or if a malicious application is running, then the write-ahead logging (WAL) could be accessed and valuable information leaked through it, since the WAL is not yet encrypted as such: raiden-network/raiden#579
Disk Full: The client does not properly handle the cases where the user’s disk may be full. This could lead to a loss of data due to the Raiden node crashing. In the future, we want to handle the detection of a full disk and gracefully quit the app: raiden-network/raiden#675
Blockchain Congestion: If the blockchain is congested and there is no space for the Raiden node to submit transactions on-chain, the client could end up being unable to settle the channel on-chain. The development of a gas slot based settlement timeout definition has been suggested in order to address blockchain congestion: raiden-network/raiden#383
Chain reorganizations: The client used to have an issue with edge cases of chain reorganizations. These issues have been hot fixed by only polling events that are confirmed for 5 blocks. Same applies to processing transactions, which are assumed to be valid only after a confirmation period of 5 blocks. This results in 15 blocks wait time for opening a channel (three on-chain transactions).
The database layout can change between versions. For patch and minor change releases, Raiden will do automatic upgrades in the background, as soon as you start the client with the new version. Your old database will always be kept as a backup.
However, for major change releases, this may not always be possible. If the client tells you, that the database migration was not possible, you are left with two options:
to recover all allocated funds, you should run the previous version of Raiden and close and settle all channels. Afterwards you can move your old database directory out of the way and join the network again with the same Ethereum keystore file.
if there are no funds worth recovering, you can also simply start over with a new Ethereum keystore file and start over. This should be true for all usage on testnet and in cases where your channel balances are very low on mainnet. Don’t hesitate to ask for help!