install failed，You have requested: deface = 1.6.2

[jjustwin]

You have requested:
deface = 1.6.2

The bundle currently has deface locked at 1.9.0.
Try running bundle update deface

If you are updating multiple gems in your Gemfile at once,
try passing them all to bundle update

[nekrasovdmitriy]

i got this while bundle update

Resolving dependencies...
Could not find compatible versions

Because redmine_plugin_kit >= 1.0.2, < 1.0.3 depends on deface = 1.8.2
  and redmine_plugin_kit < 1.0.2 depends on deface = 1.8.1,
  redmine_plugin_kit < 1.0.3 requires deface = 1.8.1 OR = 1.8.2.
So, because redmine_plugin_kit >= 1.0.3 depends on deface = 1.9.0
  and Gemfile depends on deface = 1.6.2,
  version solving has failed.

Environment:
Redmine version 5.1.1.stable
Ruby version 2.7.4-p191 (2021-07-07) [x86_64-linux-gnu]
Rails version 6.1.7.6
Environment production
Database adapter Mysql2
Mailer queue ActiveJob::QueueAdapters::AsyncAdapter
Mailer delivery smtp
Redmine settings:
Redmine theme Zenmine-510 (includes JavaScript)
SCM:
Git 2.30.2
Filesystem
Redmine plugins:
additional_tags 3.0.9
additionals 3.0.8
computed_custom_field 1.0.7
mega_calendar 1.9.6
redmine_checklists 3.1.22
redmine_custom_workflows 2.0.8
redmine_image_clipboard_paste 3.3.0
redmine_impersonate 2.0.0
redmine_issue_dynamic_edit 0.8.1
redmine_issue_view_columns 1.0.1
redmine_issues_tree 0.0.15
redmine_logs 0.3.0
redmine_mentions 0.0.1
redmine_messenger 1.0.15
redmine_workflow_hidden_fields 0.5.1
redmine_wysiwyg_editor 0.32.0
redmine_x_lightbox2 1.0.0
view_customize 3.5.1

[Arean82]

Edit the PluginGemfile

and change the third line from "gem 'deface', '1.6.2'"
to

gem 'deface', '1.8.2'

this worked for me