Job Invocations: can't convert String into an exact number

I started an ansible role and got this:

The I clicked the hostname in the bottom left to get more information on what failed and got this:

Expected outcome:
I see the output of ansible in white text on dark grey background.

Foreman and Proxy versions:

Foreman and Proxy plugin versions:
foreman-tasks 1.1.1
foreman_ansible 5.0.1
foreman_discovery 16.0.1
foreman_remote_execution 3.2.1

Distribution and version:
Debian 10.4

Other relevant data:
This is the log from /var/log/foreman/production.log:

2020-05-25T15:56:19 [I|app|057f004e] Started GET "/template_invocations/8" for at 2020-05-25 15:56:19 +0200
2020-05-25T15:56:19 [I|app|057f004e] Processing by TemplateInvocationsController#show as HTML
2020-05-25T15:56:19 [I|app|057f004e]   Parameters: {"id"=>"8"}
2020-05-25T15:56:19 [I|app|057f004e]   Rendering vendor/ruby/2.5.0/gems/foreman_remote_execution-3.2.1/app/views/template_invocations/show.html.erb within layouts/application
2020-05-25T15:56:19 [I|app|057f004e]   Rendered collection of vendor/ruby/2.5.0/gems/foreman_remote_execution-3.2.1/app/views/template_invocations/_output_line_set.html.erb [2 times] (1.2ms)
2020-05-25T15:56:19 [I|app|057f004e]   Rendered vendor/ruby/2.5.0/gems/foreman_remote_execution-3.2.1/app/views/template_invocations/show.html.erb within layouts/application (11.5ms)
2020-05-25T15:56:19 [W|app|057f004e] Action failed
2020-05-25T15:56:19 [I|app|057f004e]   Rendering common/500.html.erb within layouts/application
2020-05-25T15:56:19 [I|app|057f004e]   Rendered common/500.html.erb within layouts/application (0.6ms)
2020-05-25T15:56:19 [I|app|057f004e]   Rendered layouts/_application_content.html.erb (0.2ms)
2020-05-25T15:56:19 [I|app|057f004e]   Rendering layouts/base.html.erb
2020-05-25T15:56:19 [I|app|057f004e]   Rendered layouts/base.html.erb (1.1ms)
2020-05-25T15:56:19 [I|app|057f004e] Completed 500 Internal Server Error in 46ms (Views: 2.8ms | ActiveRecord: 7.3ms)

I have ansible-runner compiled from source, because there is no release for Debian 10, yet. It just came to my mind, that I should mention it here, maybe it is related to the problem?

Is there another log I should look for information on this?

Does anybody have a working setup with debian 10 and ansible?