When an option popup window is closed MCreator has a chance of freezing indefinitely (using almost no cpu, with no additional logs).
Both the time MCreator has been open for and the size of the element being edited appear to effect the chance of the application freezing.
Trying to import an audio file immediately after the application is launched has never resulted in it freezing, while doing this same action after the application has been open for over 5 mins will often freeze it. Selecting an item for a simple crafting recipe shortly after launching will rarely freeze it, while attempting to modify the spawn egg colors for a custom entity (which contains many pages and takes longer to load) will always cause a crash.
Finally there appears to be one thing that seems to always trigger a freeze, regardless of the element's size or the time the application has been open for: Attempting to add a variable to a procedure.
I had tried creating multiple workspaces, with each of them having the exact the same issues.