When I try to convert a PDF generated by ConTeXt LMTX to PNG using ImageMagick's convert the following happens:

   **** Error: stream Length incorrect.
               Output may be incorrect.
   **** Error:  An error occurred while reading an XREF table.
   **** The file has been damaged.  This may have been caused
   **** by a problem while converting or transfering the file.
   **** Ghostscript will attempt to recover the data.
   **** However, the output may be incorrect.
Error: /ioerror in --runpdf--
Operand stack:
   post_eof_count   4096   --nostringval--   4571
Execution stack:
   %interp_exit   .runexec2   --nostringval--   runpdf   --nostringval--   2   %stopped_push   --nostringval--   runpdf   runpdf   false   1   %stopped_push   1990   1   3   %oparray_pop   1989   1   3   %oparray_pop   1977   1   3   %oparray_pop   1978   1   3   %oparray_pop   runpdf   runpdf   runpdf   runpdf   runpdf   runpdf   runpdf
Dictionary stack:
   --dict:735/1123(ro)(G)--   --dict:1/20(G)--   --dict:80/200(L)--   --dict:80/200(L)--   --dict:135/256(ro)(G)--   --dict:315/325(ro)(G)--   --dict:28/32(L)--
Current allocation mode is local
GPL Ghostscript 9.50: Unrecoverable error, exit code 1
convert-im6.q16: FailedToExecuteCommand `'gs' -sstdout=%stderr -dQUIET -dSAFER -dBATCH -dNOPAUSE -dNOPROMPT -dMaxBitmap=500000000 -dAlignToPixels=0 -dGridFitTT=2 '-sDEVICE=pngalpha' -dTextAlphaBits=4 -dGraphicsAlphaBits=4 '-r300x300'  '-sOutputFile=/tmp/magick-55690XUwDR8veJQEc%d' '-f/tmp/magick-55690zbxNvSPCVCYe' '-f/tmp/magick-55690aVvG11u3p8wd'' (1) @ error/pdf.c/InvokePDFDelegate/291.
convert-im6.q16: no images defined `151.png' @ error/convert.c/ConvertImageCommand/3258.