<move element="element name" destination="where you want to move" after="">
Frontend Error:
1 exception(s): Exception #0 (Magento\Framework\Config\Dom\ValidationException): Element 'referenceContainer', attribute 'after': The attribute 'after' is not allowed. Line: 764 Element 'body': This element is not expected. Expected is one of ( attribute, block, referenceBlock, referenceContainer, container, move, uiComponent ). Line: 865 Exception #0 (Magento\Framework\Config\Dom\ValidationException): Element 'referenceContainer', attribute 'after': The attribute 'after' is not allowed. Line: 764 Element 'body': This element is not expected. Expected is one of ( attribute, block, referenceBlock, referenceContainer, container, move, uiComponent ). Line: 865
Backend Error:
1 exception(s): Exception #0 (LogicException): Could not create an acl object: Invalid Document Element 'resource': The attribute 'title' is required but missing. Line: 5 Element 'resource': The attribute 'title' is required but missing. Line: 6 Element 'resource': The attribute 'title' is required but missing. Line: 7 Element 'resource': The attribute 'title' is required but missing. Line: 8 Exception #0 (LogicException): Could not create an acl object: Invalid Document Element 'resource': The attribute 'title' is required but missing. Line: 5 Element 'resource': The attribute 'title' is required but missing. Line: 6 Element 'resource': The attribute 'title' is required but missing. Line: 7 Element 'resource': The attribute 'title' is required but missing. Line: 8
Front:
I think, You are using magento2.2 version. In this version, There is some modification in layout xml. You can not use after and before attribute in referenceContainer tag.
To solve this issue, You have to remove after and before attribute from referenceContainer.
you can use move tag for rearranging layout
<move element="element name" destination="where you want to move" after="">
Admin
In your /magento-root/app/code/Plazathemes/Themeoptions/etc/acl.xml file replace
<resource id="plazathemes_themeoptions::config" title="Themeoptions" />
with
<resource id="Plazathemes_Themeoptions::config" title="Themeoptions" />
Magento is looking for the id attribute with CamelCase value, which in your case seems not satisfying.