Hi! the following example compiles with MkIV but fails in LMTX: \unprotect \setupinteraction [\c!author={Foo & Bar}] %% {Foo \& Bar} works for MkIV and LMTX \protect \starttext\null\stoptext LMTX: 1 \unprotect 2 \setupinteraction 3 [\c!author={Foo & Bar}] 4 >> \protect 5 6 \starttext\null\stoptext 7 I can't figure out why you would want to use a tab mark here. If some right brace up above has ended a previous alignment prematurely, you're probably due for more error messages. mtx-context | fatal error: return code: 256 As \& works for MkIV as well as LMTX, there's an easy workaround. But maybe this isn't intended behaviour and needs checking. ConTeXt ver: 2021.07.06 18:49 LMTX Marco