I am working through the developer tutorial [here][1].

I have added two `action` buttons to a tree view.

Everything worked fine until I restarted the server after adding the `button` tags to the XML `view`. I then received the following error:

```
Traceback (most recent call last):
File "/home/keith/src/odoo/odoo/service/server.py", line 1246, in preload_registries
registry = Registry.new(dbname, update_module=update_module)
File "/odoo/modules/registry.py", line 87, in new
odoo.modules.load_modules(registry, force_demo, status, update_module)
File "/odoo/modules/loading.py", line 470, in load_modules
processed_modules += load_marked_modules(cr, graph,
File "/odoo/modules/loading.py", line 363, in load_marked_modules
loaded, processed = load_module_graph(
File "/odoo/modules/loading.py", line 222, in load_module_graph
load_data(cr, idref, mode, kind='data', package=package)
File "/odoo/modules/loading.py", line 69, in load_data
tools.convert_file(cr, package.name, filename, idref, mode, noupdate, kind)
File "/odoo/tools/convert.py", line 745, in convert_file
convert_xml_import(cr, module, fp, idref, mode, noupdate)
File "/odoo/tools/convert.py", line 811, in convert_xml_import
obj.parse(doc.getroot())
File "/odoo/tools/convert.py", line 731, in parse
self._tag_root(de)
File "/odoo/tools/convert.py", line 691, in _tag_root
raise ParseError(msg) from None # Restart with "--log-handler odoo\.tools\.convert:DEBUG"\ for\ complete\ traceback
odoo\.tools\.convert\.ParseError:\ while\ parsing\ /custom/estate/views/estate_property_offer_views\.xml:3
Invalid\ view\ estate\.property\.offer\.tree\ \(estate\.estate_property_offer_view_tree\)\ definition\ in\ estate/views/estate_property_offer_views\.xml

View\ error\ context:
'\-no\ context\-'
```

If\ I\ remove\ the\ button\ tags,\ the\ server\ starts\ without\ error
\(`\./odoo\-bin\ \-\-addons\-path=\.\./custom,addons\ \-d\ rd\-demo\ \-u\ estate\ \-\-dev\ xml`\)\.

I\ can\ then\ add\ the\ buttons\ back\ and\ they\ work\ correctly\ but\ as\ soon\ as\ I\ restart\ the\ server,\ I\ get\ the\ error\ again\.

Here\ is\ the\ complete\ record\ from\ the\ `view`:

```
\ \ \ \ "\ rel="ugc">ir\.ui\.view">
\ \ \ \ \ \ \ \ estate\.property\.offer\.tree
\ \ \ \ \ \ \ \ estate\.property\.offer
\ \ \ \ \ \ \ \
\ \ \ \ \ \ \ \ \ \ \ \
\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \
\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \
\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \
\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \
\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \
\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \
\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \
\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \
\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \
\ \ \ \ \ \ \ \ \ \ \ \
\ \ \ \ \ \ \ \
\ \ \ \
```

\ \ \[1\]:\ https://www.odoo.com/documentation/15.0/developer/howtos/rdtraining/10_actions.html