[NTG-context] \setupbackend in MkIV

I cannot get a PDF/A document produced with the latest MkIV beta 2020.05.18 16:46 (LMTX works without issue). Using the example from the wiki (https://wiki.contextgarden.net/PDF/A) I get the error stating: <inserted text> ... \p_file {\backendparameter {xmpfile}}\ifempty                                                   \p_file \else \clf_setxmpf... \setup_backend ...end [#1]\the \everysetupbackend l.11 ...ISO coated v2 300\letterpercent\space (ECI)] mtx-context     | fatal error: return code: 1 Removing either of the \setupbackend instructions still results in the same error. Same issue for PDF/X. Is it a bug, or is it me? -- Rik