[Doc] Add workaround for VM start button is not visible

[w13915984028]

Is your doc request related to a problem? Please describe or add related issue ID.

Rarely, the Start button is not shown in the VM page of Harveter WebUI, and user can not start the VM from the WebUI.

Describe the solution you'd like

Add workaround to https://docs.harvesterhci.io/v1.2/troubleshooting/index

[harvesterhci-io-github-bot]

Pre Ready-For-Testing Checklist

• If labeled: require/HEP Has the Harvester Enhancement Proposal PR submitted?
  The HEP PR is at:

• Where is the reproduce steps/test steps documented?
  The reproduce steps/test steps are at:

• Is there a workaround for the issue? If so, where is it documented?
  The workaround is at:

• Have the backend code been merged (harvester, harvester-installer, etc) (including backport-needed/*)?
  The PR is at:

  • Does the PR include the explanation for the fix or the feature?

  • Does the PR include deployment change (YAML/Chart)? If so, where are the PRs for both YAML file and Chart?
    The PR for the YAML change is at:
    The PR for the chart change is at:

• If labeled: area/ui Has the UI issue filed or ready to be merged?
  The UI issue/PR is at:

• If labeled: require/doc, require/knowledge-base Has the necessary document PR submitted or merged?
  The documentation/KB PR is at: Add troubleshooting for vm start button is not visible docs#471

• If NOT labeled: not-require/test-plan Has the e2e test plan been merged? Have QAs agreed on the automation test case? If only test case skeleton w/o implementation, have you created an implementation issue?

  • The automation skeleton PR is at:
  • The automation test case PR is at:

• If the fix introduces the code for backward compatibility Has a separate issue been filed with the label release/obsolete-compatibility?
  The compatibility issue is filed at:

[harvesterhci-io-github-bot]

Automation e2e test issue: harvester/tests#978