In environments with case-sensitive paths, the server fails to load structures named with uppercase letters, despite a matching structure file existing.

Example
http://jragoncommands.weebly.com/tempests-box.html
http://www.mediafire.com/file/0a1t26czd2e30ew/Tempest_Resources_Version_0.4.zip

Loading these structures on macOS with a case-insensitive volume works perfectly. For example, placing a new structure block and loading structure "TTB" works.

Performing the same steps on a CentOS 7 / Linux server does not work; it displays a "Structure TTB not available" error, even though TTB.nbt exists in the world's structures folder.

Workaround
Renaming all nbt structure files to their lowercase equivalents allows the server to load the structures, even with their original names. For example, renaming "TTB.nbt" --> "ttb.nbt" and loading the "TTB" structure in-game works.

Proposed Solution
The server should fully respect capitalization and save structures with filenames matching the structure's name: i.e. TTB -> TTB.nbt and then look for TTB.nbt (rather than ttb.nbt). It appears that the server currently converts the name to lower case before loading the file.

Alternatively, the server should allow loading of structures regardless of capitalization in the name, treating TTB and ttb interchangeably, loading any variation of filename. In other words, for a structure called "TTB", the server should work with any manner of capitalization of the corresponding nbt file.