Site displays blank after installing a new theme

[Bigga]

Am having problem installing theme.
Anytime i download a theme and uploaded the upload content into my forum root directory. But when i import the xmf file in my admin panel and open my site it will be blank (nothing will be showing).
This is the error am getting after importing the theme xmf file:

An exception occurred: xenforo.css - Line 79: Invalid math expression in /htdocs/library/XenForo/Template/Compiler.php on line 991
1. XenForo_Template_Compiler->getNewCompilerException() in XenForo/Template/Compiler/Function/Calc.php at line 189
2. XenForo_Template_Compiler_Function_Calc->_parseMathExpression() in XenForo/Template/Compiler/Function/Calc.php at line 105
3. XenForo_Template_Compiler_Function_Calc->_parseMathExpression() in XenForo/Template/Compiler/Function/Calc.php at line 55
4. XenForo_Template_Compiler_Function_Calc->compile() in XenForo/Template/Compiler.php at line 700
5. XenForo_Template_Compiler->compileFunction() in XenForo/Template/Compiler.php at line 576
6. XenForo_Template_Compiler->compileSegment() in XenForo/Template/Compiler.php at line 509
7. XenForo_Template_Compiler->compileSegments() in XenForo/Template/Compiler.php at line 422
8. XenForo_Template_Compiler->compileIntoVariable() in XenForo/Template/Compiler/Tag/Include.php at line 113
9. XenForo_Template_Compiler_Tag_Include->compile() in XenForo/Template/Compiler.php at line 641
0. XenForo_Template_Compiler->compileTag() in XenForo/Template/Compiler.php at line 569
1. XenForo_Template_Compiler->compileSegment() in XenForo/Template/Compiler.php at line 509
2. XenForo_Template_Compiler->compileSegments() in XenForo/Template/Compiler.php at line 372
3. XenForo_Template_Compiler->compileParsed() in XenForo/Model/Template.php at line 1601
4. XenForo_Model_Template->compileAndInsertParsedTemplate() in
XenForo/Model/Template.php at line
1479
5. XenForo_Model_Template->compileTemplateInStyleTree() in
XenForo/Model/Template.php at line
1329
6. XenForo_Model_Template->compileNamedTemplateInStyleTree() in
XenForo/Model/Template.php at line
1268
7. XenForo_Model_Template->compileAllTemplates() in XenForo/Deferred/Template.php at line 36
8. XenForo_Deferred_Template->execute()
in XenForo/Deferred/Atomic.php at line
66
9. XenForo_Deferred_Atomic->execute() in
XenForo/Model/Deferred.php at line 295
0. XenForo_Model_Deferred->runDeferred()
in XenForo/Model/Deferred.php at line
429
1. XenForo_Model_Deferred->_runInternal()
in XenForo/Model/Deferred.php at line
374
2. XenForo_Model_Deferred->run() in
XenForo/ViewRenderer/Abstract.php at line 352
3. XenForo_ViewRenderer_Abstract::hasManualDeferredToRun() in XenForo/ViewRenderer/HtmlAdmin.php at line 50
4. XenForo_ViewRenderer_HtmlAdmin->renderRedirect() in XenForo/FrontController.php at line 617
5. XenForo_FrontController->renderView() in
XenForo/FrontController.php at line 158
6. XenForo_FrontController->run() in /home/vol11_6/byethost9.com/b9_20676140/htdocs/admin.php at line
13

 

[Paul B]

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