XF 1.5 Installing themes error

[Halt03410]

So when I attempt to install or update themes on my forums I get and error saying Compiler.php didn't function properly. And it creates this error in my error logs

Error Info
XenForo_Template_Compiler_Exception: editor_contents.css - Line 80: Invalid math expression - library/XenForo/Template/Compiler.php:991
Generated By: Halt, Today at 5:45 AM
Stack Trace
#0 /var/www/vhosts/blacksunstudios.org/forums.blacksunstudios.org/library/XenForo/Template/Compiler/Function/Calc.php(189): XenForo_Template_Compiler->getNewCompilerException(Object(XenForo_Phrase))
#1 /var/www/vhosts/blacksunstudios.org/forums.blacksunstudios.org/library/XenForo/Template/Compiler/Function/Calc.php(55): XenForo_Template_Compiler_Function_Calc->_parseMathExpression(Object(XenForo_Template_Compiler), 'intval(?) + int...', Array)
#2 /var/www/vhosts/blacksunstudios.org/forums.blacksunstudios.org/library/XenForo/Template/Compiler.php(700): XenForo_Template_Compiler_Function_Calc->compile(Object(XenForo_Template_Compiler), 'calc', Array, Array)
#3 /var/www/vhosts/blacksunstudios.org/forums.blacksunstudios.org/library/XenForo/Template/Compiler.php(576): XenForo_Template_Compiler->compileFunction('calc', Array, Array)
#4 /var/www/vhosts/blacksunstudios.org/forums.blacksunstudios.org/library/XenForo/Template/Compiler.php(509): XenForo_Template_Compiler->compileSegment(Array, Array)
#5 /var/www/vhosts/blacksunstudios.org/forums.blacksunstudios.org/library/XenForo/Template/Compiler/Tag/If.php(112): XenForo_Template_Compiler->compileSegments(Array, Array)
#6 /var/www/vhosts/blacksunstudios.org/forums.blacksunstudios.org/library/XenForo/Template/Compiler.php(641): XenForo_Template_Compiler_Tag_If->compile(Object(XenForo_Template_Compiler), 'if', Array, Array, Array)
#7 /var/www/vhosts/blacksunstudios.org/forums.blacksunstudios.org/library/XenForo/Template/Compiler.php(570): XenForo_Template_Compiler->compileTag('if', Array, Array, Array)
#8 /var/www/vhosts/blacksunstudios.org/forums.blacksunstudios.org/library/XenForo/Template/Compiler.php(509): XenForo_Template_Compiler->compileSegment(Array, Array)
#9 /var/www/vhosts/blacksunstudios.org/forums.blacksunstudios.org/library/XenForo/Template/Compiler.php(422): XenForo_Template_Compiler->compileSegments(Array, Array)
#10 /var/www/vhosts/blacksunstudios.org/forums.blacksunstudios.org/library/XenForo/Template/Compiler/Tag/Include.php(113): XenForo_Template_Compiler->compileIntoVariable(Array, '__compilerVar3', Array)
#11 /var/www/vhosts/blacksunstudios.org/forums.blacksunstudios.org/library/XenForo/Template/Compiler.php(641): XenForo_Template_Compiler_Tag_Include->compile(Object(XenForo_Template_Compiler), 'include', Array, Array, Array)
#12 /var/www/vhosts/blacksunstudios.org/forums.blacksunstudios.org/library/XenForo/Template/Compiler.php(570): XenForo_Template_Compiler->compileTag('include', Array, Array, Array)
#13 /var/www/vhosts/blacksunstudios.org/forums.blacksunstudios.org/library/XenForo/Template/Compiler.php(509): XenForo_Template_Compiler->compileSegment(Array, Array)
#14 /var/www/vhosts/blacksunstudios.org/forums.blacksunstudios.org/library/XenForo/Template/Compiler.php(372): XenForo_Template_Compiler->compileSegments(Array)
#15 /var/www/vhosts/blacksunstudios.org/forums.blacksunstudios.org/library/XenForo/Model/Template.php(1601): XenForo_Template_Compiler->compileParsed(Array, 'editor_contents...', 9, 0)
#16 /var/www/vhosts/blacksunstudios.org/forums.blacksunstudios.org/library/XenForo/Model/Template.php(1480): XenForo_Model_Template->compileAndInsertParsedTemplate(1233, Array, 'editor_contents...', 9)
#17 /var/www/vhosts/blacksunstudios.org/forums.blacksunstudios.org/library/XenForo/Model/Template.php(1329): XenForo_Model_Template->compileTemplateInStyleTree(Array)
#18 /var/www/vhosts/blacksunstudios.org/forums.blacksunstudios.org/library/XenForo/Model/Template.php(1268): XenForo_Model_Template->compileNamedTemplateInStyleTree('editor_contents...', 0)
#19 /var/www/vhosts/blacksunstudios.org/forums.blacksunstudios.org/library/XenForo/Deferred/Template.php(36): XenForo_Model_Template->compileAllTemplates(1.561546087265, 0, 0)
#20 /var/www/vhosts/blacksunstudios.org/forums.blacksunstudios.org/library/XenForo/Model/Deferred.php(295): XenForo_Deferred_Template->execute(Array, Array, 2.2919840812683, 'Rebuilding... T...')
#21 /var/www/vhosts/blacksunstudios.org/forums.blacksunstudios.org/library/XenForo/Model/Deferred.php(429): XenForo_Model_Deferred->runDeferred(Array, 2.2919840812683, 'Rebuilding... T...', false)
#22 /var/www/vhosts/blacksunstudios.org/forums.blacksunstudios.org/library/XenForo/Model/Deferred.php(374): XenForo_Model_Deferred->_runInternal(Array, 2.2919869422913, 'Rebuilding... T...', false)
#23 /var/www/vhosts/blacksunstudios.org/forums.blacksunstudios.org/library/XenForo/ViewRenderer/Abstract.php(352): XenForo_Model_Deferred->run(true, 2.2919869422913)
#24 /var/www/vhosts/blacksunstudios.org/forums.blacksunstudios.org/library/XenForo/ViewRenderer/HtmlAdmin.php(50): XenForo_ViewRenderer_Abstract::hasManualDeferredToRun()
#25 /var/www/vhosts/blacksunstudios.org/forums.blacksunstudios.org/library/XenForo/FrontController.php(616): XenForo_ViewRenderer_HtmlAdmin->renderRedirect(4, 'http://forums.b...', NULL, Array)
#26 /var/www/vhosts/blacksunstudios.org/forums.blacksunstudios.org/library/XenForo/FrontController.php(158): XenForo_FrontController->renderView(Object(XenForo_ControllerResponse_Redirect), Object(XenForo_ViewRenderer_HtmlAdmin), Array)
#27 /var/www/vhosts/blacksunstudios.org/forums.blacksunstudios.org/admin.php(13): XenForo_FrontController->run()
#28 {main}
Request State
array(3) {
  ["url"] => string(68) "http://forums.blacksunstudios.org/admin.php?uix-styles/install-step2"
  ["_GET"] => array(1) {
    ["uix-styles/install-step2"] => string(0) ""
  }
  ["_POST"] => array(0) {
  }
}

I'm not familiar with Xenforo at all so I have not much of an idea as to what I should do from here. Any help is appreciated.

 

[Paul B]

That's an issue with the UI.X style - you will have to contact the author for support.

 

[Mike]

This particular error indicates that you're trying to install a newer theme on an older XenForo. You need to upgrade to XenForo 1.5.9.