A project has been processed as a text file and is now corrupted

Sometimes the following error can appear when loading a project :

[Hdf5Archive] Archive 'project.spp' appears to have been processed as a text file and is irremediably corrupted.
[Project management] The selected project 'project.spp' isn't valid!

This error means the project has been modified outside of Substance 3D Painter and cannot be read back properly .
It usually happens when a versioning software (such as Perforce ) processed the Substance 3D Painter project as a text file instead of a binary file . The only solution is to add a new rule/exception to the versioning software to force the processing of spp files as binary . For more information with Perforce , see the dedicated documentation : https://www.perforce.com/perforce/r16.1/manuals/cmdref/p4_typemap.html