Proj.db environment trouble during installation

Hello Community,

I’m new to OTB and I’m trying to link it with QGIS. I downloaded version 7.2.0 and can run it with no problem. However, when I link it with QGIS, it still looks for the proj.db file even if it set it. I set an environment variable to point to the proj folder containing the proj.db (no success in using the OTB share/proj or QGIS share/proj)


it still says:
ERROR 1:PROJ: proj_identity: Cannot find proj.db
ERROR 1:PROJ: proj_create_from_database: Cannot find proj.db

each time I use the “TrainImagesClassifier” function

I have a valid .TIF file, vector layer, and XML image statistics file used as inputs. My QGIS version is 3.4.14. Is this version compatible, by the way?

Hopefully some had the same trouble I had and successfully resolved it. Requesting for your assistance on this.


this is a bug of the QGIS plugin, when GDAL v3.X is used (this is the case for OTB binary packages 7.1 and 7.2).

The PROJ_LIB environment variable required by GDAL 3.X and PROJ 6.X is not set by the plugin, and I don’t think there is a way for the QGIS user to set it. This has been fixed in recent versions of QGIS.

This table summarizes which version of OTB is compatible with which version of QGIS. In your case you should either use QGIS >= 3.14 or OTB <= 7.0.


I hope that helps,

Good day Cédric,

Thank you for your response. I’ll downgraded to 7.0 and I was able to get the training done. There was one slight problem encountered, which you answered in one of the posts:

Applying this additional solution to OTB 7.0 and QGIS 3.4.14 finally created a model.

Thank you very much for your help!


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I am experiencing a similar problem with QGIS 3.16 and OTB-7.1.0.
ERROR 1: PROJ: proj_identify: Cannot find proj.db
…[repeated then ]
ERROR 1: PROJ: proj_create_from_database: Cannot find proj.db

Any suggestions?


which OS Are you using ?

I have no problem using OTB 7.1.0 and QGIS 3.16 on Ubuntu.

Can you find the proj.db file in OTB-7.1.0/share/proj ?


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Hi Cedric,
I’m using OTB 7.1.0 and QGIS 3.16 on Win 10.
I found my proj.db in C:\OTB-7.1.0\share\proj and set the environmental variable PROJ_LIB to that path but it didn’t work.