[Fixed]-'ManyToManyField' object has no attribute 'm2m_reverse_field_name'

You have to make sure that the model you are creating the ‘ManyToManyField’ is already created in the database.

You can do that by adding as a dependency the migration where the model is created to your migration in which you alter the field:

Scenario 1: You alter the field to ‘ManyToManyField’ with a model from other app

class Migration(migrations.Migration):

    dependencies = [
      ..........
      ('[app]', '__first__'),
    ]

    operations = [
       .........
    ]

Scenario 2: You create a ‘ManyToManyField’ and the model you are referring to is in the same file:

 class Migration(migrations.Migration):

    dependencies = [
      ..........
    ]

    operations = [
       .........
       # Make sure the model you are making the reference with is  before the ManyToManyField
       migrations.CreateModel(...) ,
       migrations.AlterField/CreateField(...)

    ]

I ran into the same problem, but I don’t know if for the same reasons. Luckily I don’t have any important data in the system, so I just changed the migration as follows – but note that this deletes all data in these columns!

Before:

operations = [
    migrations.AlterField(
        model_name='resource',
        name='authors',
        field=models.ManyToManyField(related_name='resources_authored', to='api.Person'),
    ),
    migrations.AlterField(
        model_name='resource',
        name='editors',
        field=models.ManyToManyField(blank=True, related_name='resources_edited', to='api.Person'),
    ),
]

After:

operations = [
    migrations.RemoveField(
        model_name='resource',
        name='authors',
    ),
    migrations.RemoveField(
        model_name='resource',
        name='editors',
    ),
    migrations.AddField(
        model_name='resource',
        name='authors',
        field=models.ManyToManyField(related_name='resources_authored', to='api.Person'),
    ),
    migrations.AddField(
        model_name='resource',
        name='editors',
        field=models.ManyToManyField(blank=True, related_name='resources_edited', to='api.Person'),
    ),
]

While the altering failed for mysterious reasons, removing and recreating the fields worked.

One of the reason might be your api.Person model migrations might not have run before the one in which it is referenced(in your example it is file_manager.0006_auto_20160109_1536). So make sure api.Person migrations are run before, by adding them in the dependencies of file_manager.0006_auto_20160109_1536.

I had the same problem when I tried to rename a table which was referenced with a many to many fields.
I resolved it this way:
– dumped the manytomany relationship data into a file
– removed the manytomany field and migrated
– renamed the table and migrated
– added the manytomany field back and migrated and loaded the relationships from the dump

I also had the same problem, but the way that I fixed it, is the following steps:
Nota: You will lose data from that ManyToManyField

python manage.py makemigrations app_name
python manage.py migrate app_name --fake

Don’t forget the –fake

After that.
I removed (or just comment the line) the ManyToMany field, and then makemigrations app_name, migrate app_name.

At this step you have this column from your database cleared, what you need to do now is to re add the ManyToManyField, so when you makemigrations app_name & migrate app_name again.
You server can run perfectly

It’s not the best, but it worked for me.
hope it will help !

My problem came with changing a field from a choices field to a manytomanyfield.

If you do this and keep the same name, then you’ll have issues.

I followed Denis Drescher:

Basically go through your migration files and check what django is doing with these fields.

If django is doing migrations.AlterField for the field which was a choices field and is now a manytomanyfield, change it to
migrations.RemoveField and then Migrations.AddField

I had no meaningful data as yet, so I deleted the database(db.sqlite3) and all migrations(0001,0002 etc)

Simply check if you renamed model-related attributes or anthing related to the model in the admin before you drop the db.
Actually it worked for me.