When I try and save the resource I get: Spatial context extent appears to be invalid (or Default).

The XML:

<?xml version="1.0"?>

OSGeo.Gdal.3.4 Default This coordinate system has been overridden. LOCAL_CS["XY-MT",LOCAL_DATUM["X-Y",10000],UNIT["Meter", 1],AXIS["X",EAST],AXIS["Y",NORTH]] LOCAL_CS["XY-MT",LOCAL_DATUM["X-Y",10000],UNIT["Meter", 1],AXIS["X",EAST],AXIS["Y",NORTH]] Dynamic -10000000 -10000000 10000000 10000000 0.001 0.001


These sids are 205mb a piece and theirs 53 of them (sat images). I decoded them to geotiff and they came out 2+gig ea.

What do I need to do to get these to display in MG? Whats the smartest method to get them web ready?

  • How do you tell if your sids are G3 or G2? Mar 16, 2011 at 18:52
  • Grab the MrSID GeoInfo tool from here: lizardtech.com/downloads/tools.php - it will tell you if it's MG2 or MG3 encoding.
    – mwalker
    Mar 16, 2011 at 19:11
  • Seems I dont have the GDAL plugin dll's and the MrSID dll's in my MG install dirs. Loading the resource went off without a bark though... odd. dlin the lizard tech tool.. Has anyone here got the g3 sids to work on MG 2.1 GDAL 1.6 3.4? Mar 16, 2011 at 19:16

2 Answers 2


I'm guessing you're authoring this through Maestro right?

I've gotten this error too. Here's how i fixed it:

I dont remember why, but Gdal 1.6 didn't do it for me, i had to upgrade to the latest stable version of 1.8 (may work with 1.7, but why use older one?). You can probably compile this yourself or get FWTools, which may have the latest version of Gdal.

Then after you've loaded it the mrsid file (i do it from alias directory in mapguide) from Maestro:

  • click the “Edit configuration document” button on the bottom right,
  • scroll to the bottom of the xml document and find the tags MinX MinY MaxX MaxY. You would probably see the messed up extents (something like 1000000)
  • Enter the actual extents of the sid file (you can find this with any other tool like gdalinfo, arcview, and im sure anything from lizardtech)
  • Save that and you should be done

Let me know how it goes. This worked for me... Good luck!

  • Theirs 53 of them. Im going to have to put all the values for each? Mar 21, 2011 at 13:42
  • yea, i had to do that with each of my sid layer.. if they're all the same extent, copy and paste will be your friend. of course, make sure this solution actually works for one of the sid layers first before you fix them all i guess. oh, and my images are mg3 too.
    – janechii
    Mar 21, 2011 at 16:07
  • Their a composite of Orthophotos (sat img's). 205mb a piece and 2 gig decoded. Where can I get the right values and where should I plug them it? Theirs like 53 of them. Mar 23, 2011 at 14:08
  • what about these values: <gml:boundingBox> <gml:pos>-10000000 -10000000</gml:pos> <gml:pos>10000000 10000000</gml:pos> </gml:boundingBox> Mar 24, 2011 at 14:21
  • Also in arcView should I use the Display extent or the layer extent? Mar 24, 2011 at 14:41

http://trac.osgeo.org/mapguide/wiki/MGOS21GdalProvider This looks promising..

  • Still can see any sid. help Mar 16, 2011 at 20:04

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.