Not able to upload files ..( Only .txt are getting uploaded)

I just tried installing nextcloud with the help of Web Installer , everything was fine untill I tried uploading a logo. While uploding logo it got stuck with rotating uploding symbol. I tried uploading files however it is getting stuck in uploading . I am only able to upload .txt files . I Error log I found this “”"*****************

Error: Call to undefined function OCA\Theming\mime_content_type()

  1. /home/avirm2ko/public_html/cloud/apps/theming/lib/IconBuilder.php - line 69:OCA\Theming\IconBuilder->renderAppIcon(“settings”, 128)
  2. /home/avirm2ko/public_html/cloud/apps/theming/lib/Controller/IconController.php - line 126:OCA\Theming\IconBuilder->getFavicon(“settings”)
  3. /home/avirm2ko/public_html/cloud/lib/private/AppFramework/Http/Dispatcher.php - line 166:OCA\Theming\Controller\IconController->getFavicon(“settings”)
  4. /home/avirm2ko/public_html/cloud/lib/private/AppFramework/Http/Dispatcher.php - line 99:OC\AppFramework\Http\Dispatcher->executeController(OCA\Theming\ … {}, “getFavicon”)
  5. /home/avirm2ko/public_html/cloud/lib/private/AppFramework/App.php - line 118:OC\AppFramework\Http\Dispatcher->dispatch(OCA\Theming\ … {}, “getFavicon”)
  6. /home/avirm2ko/public_html/cloud/lib/private/AppFramework/Routing/RouteActionHandler.php - line 47:OC\AppFramework\App::main(“OCA\Themin … r”, “getFavicon”, OC\AppFramew … {}, { app: "sett … "})
  7. <<closure>>OC\AppFramework\Routing\RouteActionHandler->__invoke({ app: "sett … "})
  8. /home/avirm2ko/public_html/cloud/lib/private/Route/Router.php - line 297:call_user_func(OC\AppFramew … {}, { app: "sett … "})
  9. /home/avirm2ko/public_html/cloud/lib/base.php - line 987:OC\Route\Router->match("/apps/themi … s")
  10. /home/avirm2ko/public_html/cloud/index.php - line 42:OC::handleRequest()
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