No error message appears in the chat or game log when attempting to save a structure that contains uppercase characters. The structure file also doesn't appear in the "generated" folder if that's the case.
To reproduce place down a structure block, switch it to SAVE mode, input a name containing an uppercase character, click "Done". Come back to the GUI to press "Save". Notice no error message appearing and no structure file being generated.
This leads to confusion and (probably) bug reports similar to MC-122831
Linked issues
is duplicated by 12
relates to 2
Comments 3
I am unsure if this is a bug. I guess since there is no catching of the ExecutionException fatal error. This is to be expected as the log shows Non [a-z0-9/._-] character in path of location: minecraft:doubleMover
and I don't relive it is good to have a fatal error. Recommend a catch statement that sends the player a message (in red) stating(until otherwise) "Sorry, the name '"+((user input))+"' has characters that are not _lowercase_ *a-z*, *0-9* or '*/*', '*.*', '*_*' or '*-*'"
Note: this fatal error was seen (in the log) in version 18w03b.
Also, I may be helpful to show all fatal errors in-game asking the player to report if fatal error has not been logged; At least for snapshots.
Confirmed for 17w50a