Entire ldtk file becomes corrupted if multilines (possibly regular string too?) contains a backslash

[Nifflas]

To reproduce, load the ldtk file in the zip. Open it in ldtk (this will work nicely), save the file. Close ldtk, then try opening the file you just saved again. It will now be corrupted.

Basically, it becomes corrupted on the second time it's saved, not the first (which is what's included in the zip file).

Broken.zip

[cspotcode]

Possibly related to https://github.com/deepnight/ldtk/issues/992#issuecomment-2731453274