安装成功，但进入后台管理页面提示如下：
Fatal error: Uncaught RuntimeException: Missing BC Math or GMP extension. in /home/beginner/websites/g21405f419/iCMS/iPHP/library/Hashids/src/Hashids.php:420 Stack trace: #0 /home/beginner/websites/g21405f419/iCMS/iPHP/library/Hashids/src/Hashids.php(106): Hashids\Hashids->getMathExtension() #1 /home/beginner/websites/g21405f419/iCMS/iPHP/library/vendor/Vendor.Hashids.php(23): Hashids\Hashids->__construct('shXTwacKsrrGh8V...', '16') #2 /home/beginner/websites/g21405f419/iCMS/iPHP/core/iVendor.class.php(53): Vendor_Hashids->__construct(Array) #3 /home/beginner/websites/g21405f419/iCMS/iPHP/iPHP.class.php(520): iVendor::run('Hashids', Array, false) #4 /home/beginner/websites/g21405f419/iCMS/iPHP/core/iWAF.class.php(63): iPHP::vendor('Hashids', Array) #5 /home/beginner/websites/g21405f419/iCMS/app/admincp/admincp.class.php(48): iWAF::CSRF_token('1') #6 /home/beginner/websites/g21405f419/iCMS/app/admincp/admincp.class.php(65): admincp::init() #7 /home/beginner/websites/g21405f419/iCMS/admincp.php(16): admincp::run() #8 {main} in /home/beginner/websites/g21405f419/iCMS/iPHP/library/Hashids/src/Hashids.php on line 420

环境：deepin linux + apache2.4 + mysql 5.6 + php 7.3

已解决：
> sudo apt-get install php-bcmath
> sudo service apache2 restart
OK 了