My issue is similar to the one described at https://www.drupal.org/node/2712863
The only difference to the described problem is that I already have file_entity enabled and this problem occurs only with certain file types (like .zip).

Problem/Motivation

1. Install file_entity
2. Upload a .zip file using a field on some entity
3. Go to file administration /admin/content/files and edit the uploaded file
3. Replace the file or just click "Save"
Unexpected result:

PluginNotFoundException: The "entity:file:undefined" plugin does not exist. in Drupal\Core\Plugin\DefaultPluginManager->doGetDefinition()

Comments

rutiolma created an issue. See original summary.

rutiolma’s picture

rutiolma
Location 🇵🇹
CreditAttribution: rutiolma commented
Priority: Normal » Minor

Ok, actually this is just a matter of configuration.
There should be a file-type for "less common" MIME types at /admin/structure/file-types (not just Document, Image, Audio...)

IMO a "Generic" file type should be set by default, accepting all MIME types, with a lower relevance than any other types, otherwise the user will get these errors

gmangones’s picture

gmangones CreditAttribution: gmangones commented

Hi, worked fine, Thank's

tcrawford’s picture

tcrawford CreditAttribution: tcrawford commented

I was suddenly seeing this issue on Drupal 10.2 where we have file_entity still installed.
The missing mime-type was "application/octet-stream" when uploading a pdf via a managed file widget.
To debug, place a stop point in the function file_entity_file_type(FileInterface $file) to determine what the mime type is that is not resolving.
Add the missing mime type to an existing (or new) file type at /admin/structure/file-types
A more sustainable solution would be to migrate away from file_entity.