Could not load model ModelName, undefined method `has_one_attached'

[Saleh-Salem]

I am workin on project
Ruby version => 2.7.1
Rails Version => 6.0.3.2

I add rails admin gem on project => gem 'rails_admin'

It worked fine.
But after few days get issue when back to project and run rails server to complete my work, I get issue
[RailsAdmin] Could not load model Project, assuming model is non existing. (undefined method has_one_attached' for #Class:0x00005585f7ed0bc0)`

I follow all steps in this issue 3025 but not solved my issue

[mshibuya]

I believe this should be the same issue as #3025, describing what actually you did will help find the issue.