I also get "IOException encountered while reading from a byte array input stream on Welcome page after the upgrade.
Same issue as here : (Welcome page-IOException encountered while reading from a byte array input stream)
Loading last opened items failed with status: FetchError: There was an error fetching a resource: Internal Server Error. Additional information: IOException encountered while reading from a byte array input stream.
Looks like there isn`t an immediate solution provided in that topic but also wondering if anyone knows workaround to fix these issues would be helpful.