Error message were easier to interpret.
Error messages could possibly be improved by highlighting the solution in bright yellow, if it is something in plain language like "Please reload and try again", or even a link to click to solve the problem. More details of the problem could still be included outside the highlighted part or in a "read more" link, but volunteers in the moment don't want to read about the problem, only make the problem go away instantly. For example, in @Event > Create Invoices > bidder number.
Tom H. commented
There might also be better validation errors for if you are trying to setup a bidding station, you should get "eBidding not enabled" instead of Technical Difficulties. Or, if trying to delete a patron, tell you why you can't delete them.