Repos' tag file view gives error

version 12.8.1
When users goto project->repo->file tree-view in webui.
Click branch/tags drop down and select a tag. They get an error “An error occurred while fetching folder content.”
All tags across all projects give the error “An error occurred while fetching folder content.”
Select a branch and displays file tree as expected.

possible error message

{“severity”:“ERROR”,“time”:“2020-02-27T19:14:23.311Z”,“correlation_id”:“pf2qTe9X8L9”,“tags.correlation_id”:“pf2qTe9X
8L9”,“tags.locale”:“en”,“extra.server”:{“os”:{“name”:“Linux”,“version”:"#1 SMP Mon May 21 18:11:42 CDT 2018",“build”
:“3.10.0-862.3.2.el7.x86_64”,“kernel_version”:“Linux gitlab.corvidtec.com 3.10.0-862.3.2.el7.x86_64 #1 SMP Mon May 2
1 18:11:42 CDT 2018 x86_64 x86_64 x86_64 GNU/Linux”},“runtime”:{“name”:“ruby”,“version”:“ruby 2.6.5p114 (2019-10-01
revision 67812) [x86_64-linux]”}},“exception.class”:“NoMethodError”,“exception.message”:“undefined method tree' for #\u003cRugged::Tag::Annotation:0x00007f17aaae59c0\u003e","exception.backtrace":["lib/gitlab/git/rugged_impl/tree.rb :79:in get_tree_entries_from_rugged’”,“lib/gitlab/git/rugged_impl/tree.rb:37:in tree_entries_from_rugged'","lib/gi tlab/git/rugged_impl/tree.rb:26:in tree_entries_with_flat_path_from_rugged’”,“lib/gitlab/git/rugged_impl/use_rugged
.rb:28:in block in execute_rugged_call'","lib/gitlab/gitaly_client/storage_settings.rb:31:in block in allow_disk_a
ccess’”,“lib/gitlab/temporarily_allow.rb:9:in temporarily_allow'","lib/gitlab/gitaly_client/storage_settings.rb:31: in allow_disk_access’”,“lib/gitlab/git/rugged_impl/use_rugged.rb:25:in execute_rugged_call'","lib/gitlab/git/rugge d_impl/tree.rb:19:in tree_entries’”,“lib/gitlab/git/tree.rb:21:in where'","app/models/tree.rb:17:in initialize’”,
“app/models/repository.rb:673:in new'","app/models/repository.rb:673:in tree’”,“app/graphql/resolvers/tree_resolve
r.rb:23:in resolve'","lib/gitlab/graphql/generic_tracing.rb:40:in with_labkit_tracing’”,“lib/gitlab/graphql/generi
c_tracing.rb:30:in platform_trace'","lib/gitlab/graphql/generic_tracing.rb:40:in with_labkit_tracing’”,“lib/gitlab
/graphql/generic_tracing.rb:30:in platform_trace'","lib/gitlab/graphql/generic_tracing.rb:40:in with_labkit_tracin
g’”,“lib/gitlab/graphql/generic_tracing.rb:30:in platform_trace'","app/graphql/gitlab_schema.rb:46:in execute’”,“a
pp/controllers/graphql_controller.rb:48:in execute_query'","app/controllers/graphql_controller.rb:19:in execute’”,
“app/controllers/application_controller.rb:478:in set_current_admin'","app/controllers/application_controller.rb:46 3:in set_locale’”,“lib/gitlab/application_context.rb:46:in block in use'","lib/gitlab/application_context.rb:46:in use’”,“lib/gitlab/application_context.rb:19:in with_context'","app/controllers/application_controller.rb:454:in
set_current_context’”,“lib/gitlab/error_tracking.rb:34:in with_context'","app/controllers/application_controller.rb :554:in sentry_context’”]}

TIA

Update:
When you add a message to a tag it causes the webui to break.

“lightwieght” tags work as expected