Unable to get metadata for resource agent 'stonith:fence_watchdog' (SyntaxError:JSON.parse:unexpected character at line 1)

pcs 0.10.14 resource-agents 4.11.0 pacemaker 2.1.5 corosync 3.1.0
When I refresh the web page,a pop-up window appears on the page.The pop-up content is as follows.

Unable to get metadata for resource agent 'stonith:fence_watchdog' (SyntaxError:JSON.parse:unexpected character at line 1)
Warning:Agent 'pacemaker_fenced' is not installed or does not provide valid metadata:Element content failed to validate content,line 30...

I tried to execute ' pcs stonith describe fence_watchdog'
[root@node1 resource-agents]# pcs stonith describe fence_watchdog
Warning: Agent 'pacemaker-fenced' is not installed or does not provide valid metadata: Element content failed to validate content, line 30
Warning: Agent 'pacemaker-fenced' is not installed or does not provide valid metadata: Element content failed to validate content, line 30

Start by reproducing the web-page refresh error and the `pcs stonith describe fence_watchdog` command with the listed pcs, resource-agents, pacemaker, and corosync versions. Trace why the `fence_watchdog` or `pacemaker-fenced` metadata is not valid JSON or XML; done means both the page and command return valid metadata without the reported warnings.

Written by the indexing model from the issue text.