Error installing package

[lottaar]

When trying to install the package I've created with Fred I get the following error and the Fred template isn't installed.

template_err_createArray
Error saving vehicle object of class modTemplate; criteria: Array
(
    [templatename] => My template
)
Could not install related objects with foreign owned keys for vehicle object of class FredThemedTemplate; criteria: Array
(
    [template] => 
    [theme] => 2
)
Skipping vehicle object of class modLexiconEntry (data object exists and cannot be upgraded); criteria: Array
(
    [name] => setting_fred.theme.my-template.theme_dir_desc
)

Using MODX 2.8.1, Fred 1.2.1 and PHP 7.4.13.