# Mimetype mapping problem

**URL:** <https://help.nextcloud.com/t/mimetype-mapping-problem/8365>\
**Category:** ℹ️ Support\
**Created:** [February 2, 2017, 1:18pm UTC](https://help.nextcloud.com/t/mimetype-mapping-problem/8365 "2017-02-02T13:18:27Z")\
**Posts on this page:** 1\
**Showing post:** 2

<div class="post-metadata">

**Author:** ![eneiluj](https://help.nextcloud.com/user_avatar/help.nextcloud.com/eneiluj/32/2026_2.png) [@eneiluj](https://help.nextcloud.com/u/eneiluj)\
**Post date:** [March 15, 2017, 7:06pm UTC](https://help.nextcloud.com/t/mimetype-mapping-problem/8365/2 "2017-03-15T19:06:17Z")

</div>

Hi, to get the personal mimetypemapping.json changes effective for existing files, you have to rescan your files. No need to execute “update-js” command.

To do it :

```
sudo -u www-data php /var/www/html/nextcloud/occ files:scan --all

```

I guess your files that were opened correctly were created after your mimetypemapping.json modification.

Is it ok now ?

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_[View the full topic](https://help.nextcloud.com/t/mimetype-mapping-problem/8365)._