Blender ошибка при импорте obj

Imported objects from other file formats, are often times really small, off centered, or very far away from scene origin, compared to the default scene scale.

First step is to make sure anything was actually imported. Look in the Outliner for new objects under current collection (geometry should be of mesh type). If there are any, use the Outliner to select them.

Then with the mouse over the 3D View press the Numpad . (Period) key, or go to View > Frame Selected for 2.8+, to view selected objects.
This will zoom in tightly on the selected object.

If the objects are too small or too big in relation to default scene scale you may still be able to see them due to being outside the view distance bounds.

If that is the case you may been to adjust clipping distances, either for the viewport, camera or both.

Working with scene scales too large or too small may lead to float point precision issues. Blender and Cycles render are set up to work best with 1 Blender Unit = 1 Meter, both in terms of lighting and physics. If your objects are in millimetres, Kilometres or very far from this scale range you may want to scale them up or down to fit roughly in that scale range, to avoid future issues.

You stumbled upon a curious problem with filename handling in the .obj format, that isn’t well defined in the specification. I will discuss this with the Blender devs, perhaps the importer needs small adjustments to parse the file correctly under these specific circumstances. Since it worked in 2.79b it can be considered a regression.

TL;DR The handling for filenames with blanks isn’t well defined in the .obj format specification and Blender expected a different format than what was provided in your file.

The Problem

The .obj is a text format for storing 3D models. The format contains various attributes that describe the geometry of the model. Typically the .obj is accompanied by a .mtl which describes the material and textures applied to the model. In order to keep track which files belong together, the .obj may contain a mtllib attribute followed by the filename of the .mtl.

Usually the beginning of an .obj would look something like this:

# Blender v2.80 (sub 74) OBJ File: ''
# www.blender.org
mtllib test.mtl
o Cube
v 1.000000 1.000000 -1.000000
v 1.000000 -1.000000 -1.000000

In case of your file it is:

# 
mtllib "tree stump1 original model.mtl"
usemtl tree_stump1_original_model
v 4.136163 -1.200306 -10.798826 0.113725 0.152941 0.141176
v 4.140683 -1.205297 -10.794383 0.117647 0.156863 0.145098

Notice that the filename contains quotations marks. This is causing the problem. The software you used to export this model quoted the filename to avoid confusion on how to interpret the filename. While this is common practice in other file formats the specification for .obj doesn’t mention quoting filenames and says specifically:

Blank space and blank lines can be freely added to the file to aid in formatting and readability.

Which can be interpreted as blanks in filenames can be stored as is, which is precisely what Blender does. Unfortunately Blender’s importer doesn’t expect the quotation marks in the filename therefore misinterpreting the correct filepath. This results in the aforementioned error in your question.

The Fix

Open the .obj file in a text editor of your choice an remove the quotes and save. It should look like this:

# 
mtllib tree stump1 original model.mtl
usemtl tree_stump1_original_model
v 4.136163 -1.200306 -10.798826 0.113725 0.152941 0.141176

The file can now be imported by Blender.