The primary bugs involve world conversion. 1.12.2 worlds need to be converted to the new 1.13 block types, since the way blocks and block states are represented in the server has changed in 1.13. Amongst the most severe are those involving chest blocks losing part of their inventory.
Due to these bugs, along with the general performance regarding chunk loading and generation, is why Tech Fortress has not updated to 1.13. The current expectation is that 1.13 will be stable a few weeks after Mojang releases 1.13.2 and there are no severe world conversion bugs.
In the meantime, we are also testing 1.13 on the test server, named Test Fortress. You can help test bugs to keep track of as the Test Fortress server is updated. The current checklist for 1.13-readiness for the server is as follows:
- Server boots up and can be joined.
- Nothing is lost in the world; 1.13 world conversion has no bugs. (bugs exist)
- GriefPrevention claims plugin function as expected - claims protect blocks and entities, particularly new blocks and entities, etc. (a 1.13 version is currently installed)
- The rest of the plugins function as intended such as /report