This usually means that the server you are working at is very busy. Given that it occurred across multiple actions, the best first-pass solution is to wait a bit then try again.
It looks like you are working on your own Galaxy server. A local Galaxy server uses your own computer for computational resources unless you configured it differently. Also, the version of Galaxy appears to be a few years out of date.
Upgrading your server would be a very good idea, especially if you installed newer tools: Releases — Galaxy Project 21.01 documentation
Advanced configuration help is here: Galaxy Deployment & Administration — Galaxy Project 21.01 documentation
Admin training is here: GitHub - galaxyproject/admin-training: Galaxy Admin Training