The error is due to an invalid date format being saved to the custom_rmh_rooms_history SQL table.
To resolve this issue, the Windows Regional settings need to be modified and the Short Date format needs to be in MM/dd/yyyy format.

You can change the short date format for a specific user using the Regional Settings tool in Control Panel:
  1. Log on using the user account you want to configure.
  2. Click Start, point to Settings, click Control Panel, and then double-click Regional Settings.
  3. On the Date tab, click the date format you want to use in the Short date style box, and then click OK.
  4. Log off Windows, and then log on to Windows again to save the setting.
Regional Settings
For additional details on changing the regional settings, please review the following article from Microsoft:
How to Configure the Short Date Format in Windows
 
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