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This says that the component is not installed. This tells me that the component is not fully installed in Joomla. Try installing the package twice in a row, without uninstalling it before or in between. If you still have a problem something is wrong with your site's #__extensions or #__assets tables, the two tables Joomla uses when installing an extension.

PS: Since you are using Joomla 3 I hope that you have noticed there are two separate versions of ContactUs. You need version 3.0.7 which is the last version compatible with Joomla 3. If you try to install version 4 it might appear to install but since it's a Joomla 4 native component it will not actually do anything and very likely throw an error when you try to access it.

This is really something that comes from Joomla. I have no control over it nor can I help in any way. You can always try uninstalling and reinstalling the package. Beyond that, you'd need to know how Joomla works and do some database surgery.