Error Message when loading DEMs

[joewheaton]

The Problem

I am not sure how much testing of GCD we have seen post 10.6/7 but we have run exercises 100's of times on the Feshie example data and never had a problem. Now that I am teaching with GCD again, I have seen about six students run into a simple problem when loading the DEMs we provide. I cannot figure out what is causing it.

Unhelpfully, they can push past it usually by starting over, rebooting, etc. But it should not be happening in first place.

See one student's issue here).

Reproduction steps

1. Follow my instructions here (also happened on two other demos)

Exception message

@philipbaileynar any thoughts?

[philipbaileynar]

Are you able to reproduce the problem reliably? Does it happen every time if you follow a certain workflow?

[joewheaton]

I have not... that is what is worrying. I have not yet noticed any rhyme or reason on this. Lets keep this open so if we have more of these issues we can log them here and see if there is something we can figure out. About the only common thread I see is a newer version of ArcGIS (i.e. > 10.7.X). Note, this is different than #393 (even though they seem related).

[philipbaileynar]

This type of error suggests one of the following issues:

1. Another process still has the raster locked. Either Tin2Raster or another process. Perhaps the raster was just generated and GCD can't access it. Or another piece of software using it.
2. The file path is a problem. Perhaps it's on an SSD or its in a Cloud drive folder and the cloud software is attempting to change the file (because another user is accessing it - e.g. they added it to a map and the cloud software has it locked while writing pyramids)
3. Perhaps the download or unzip broke? Or the person who zipped file he files included an esri lock file in the zip archive (because they made the zip with the layer in an arcmap document).

The issue certainly smells like one caused by very specific local conditions on the users computer. These are the hardest problems to track down.

[joewheaton]

Thanks @philipbaileynar, even the above is a helpful list of possibilities for users to consider.

[Carolinah23]

Hello!
I just wanted to let you know that I am having a similar problem when using the Standalone version. I am using two DEMs and I am sure that both DEMs are in the same coordinate system, I can open both in QGIS, the files are .tif and overlap, but only one file is received by GCD. With the other, I got this error.

EDIT: In QGIS I exported the raster file that was having problems with the same information and reference system and the same folder and worked! Not sure why or how.