I'm with the exact same problem here, I've noticed that there are some console errors logged as well, but don't know for sure if they are directly related;
Anyway, I've installed Magento CE 2.3.4 on Xampp 7.2.27 and at first, it didn't even load (all I could see was a blank screen, which I've fixed with this: https://meetanshi.com/blog/solved-magento-2-2-7-and-2-3-admin-page-blank-issue/) but now, the spinner keeps on the screen just like yours and the icons aren't displaying correctly too.
I've read some suggestions to clear the cache or going with incognito mode (that I've also tried on firefox) and nothing seems to work.
this is the last `var/report` that I've got:
{"0":"Class Magento\\Framework\\View\\Element\\Template\\File\\Validator does not exist","1":"#1 Magento\\Framework\\ObjectManager\\Definition\\Runtime->getParameters('Magento\\Framewor...') called at [vendor\\magento\\framework\\ObjectManager\\Factory\\Dynamic\\Developer.php:48]\n#2 Magento\\Framework\\ObjectManager\\Factory\\Dynamic\\Developer->create('Magento\\Framewor...') called at [vendor\\magento\\framework\\ObjectManager\\ObjectManager.php:70]\n#3 Magento\\Framework\\ObjectManager\\ObjectManager->get('Magento\\Framewor...') called at [vendor\\magento\\framework\\ObjectManager\\Factory\\AbstractFactory.php:167]\n#4 Magento\\Framework\\ObjectManager\\Factory\\AbstractFactory->resolveArgument(array('instance' => 'Magento\\Framewor...'), 'Magento\\Framewor...', NULL, 'context', 'Magento\\Backend\\...') called at [vendor\\magento\\framework\\ObjectManager\\Factory\\AbstractFactory.php:273]\n#5 Magento\\Framework\\ObjectManager\\Factory\\AbstractFactory->getResolvedArgument('Magento\\Backend\\...', array('context', 'Magento\\Framewor...', true, NULL, false), array('layoutReaderPool' => array('instance' => 'pageConfigRender...'), 'generatorPool' => array('instance' => 'pageLayoutGenera...'), 'template' => 'Magento_Theme::r...', 'pageConfigRender...' => array('instance' => 'Magento\\Develope...'))) called at [vendor\\magento\\framework\\ObjectManager\\Factory\\AbstractFactory.php:236]\n#6 Magento\\Framework\\ObjectManager\\Factory\\AbstractFactory->resolveArgumentsInRuntime('Magento\\Backend\\...', array(array('context', 'Magento\\Framewor...', true, NULL, false), array('layoutFactory', 'Magento\\Framewor...', true, NULL, false), array('layoutReaderPool', 'Magento\\Framewor...', true, NULL, false), array('translateInline', 'Magento\\Framewor...', true, NULL, false), array('layoutBuilderFac...', 'Magento\\Framewor...', true, NULL, false), array('generatorPool', 'Magento\\Framewor...', true, NULL, false), array('pageConfigRender...', 'Magento\\Framewor...', true, NULL, false), array('pageLayoutReader', 'Magento\\Framewor...', true, NULL, false), array('template', NULL, true, NULL, false), array('isIsolated', NULL, false, false, false), array('entitySpecificHa...', 'Magento\\Framewor...', false, NULL, false)), array('layoutReaderPool' => array('instance' => 'pageConfigRender...'), 'generatorPool' => array('instance' => 'pageLayoutGenera...'), 'template' => 'Magento_Theme::r...', 'pageConfigRender...' => array('instance' => 'Magento\\Develope...'))) called at [vendor\\magento\\framework\\ObjectManager\\Factory\\Dynamic\\Developer.php:34]\n#7 Magento\\Framework\\ObjectManager\\Factory\\Dynamic\\Developer->_resolveArguments('Magento\\Backend\\...', array(array('context', 'Magento\\Framewor...', true, NULL, false), array('layoutFactory', 'Magento\\Framewor...', true, NULL, false), array('layoutReaderPool', 'Magento\\Framewor...', true, NULL, false), array('translateInline', 'Magento\\Framewor...', true, NULL, false), array('layoutBuilderFac...', 'Magento\\Framewor...', true, NULL, false), array('generatorPool', 'Magento\\Framewor...', true, NULL, false), array('pageConfigRender...', 'Magento\\Framewor...', true, NULL, false), array('pageLayoutReader', 'Magento\\Framewor...', true, NULL, false), array('template', NULL, true, NULL, false), array('isIsolated', NULL, false, false, false), array('entitySpecificHa...', 'Magento\\Framewor...', false, NULL, false)), array('layoutReaderPool' => array('instance' => 'pageConfigRender...'), 'generatorPool' => array('instance' => 'pageLayoutGenera...'), 'template' => 'Magento_Theme::r...', 'pageConfigRender...' => array('instance' => 'Magento\\Develope...'))) called at [vendor\\magento\\framework\\ObjectManager\\Factory\\Dynamic\\Developer.php:59]\n#8 Magento\\Framework\\ObjectManager\\Factory\\Dynamic\\Developer->create('Magento\\Backend\\...', array()) called at [vendor\\magento\\framework\\ObjectManager\\ObjectManager.php:56]\n#9 Magento\\Framework\\ObjectManager\\ObjectManager->create('Magento\\Backend\\...', array()) called at [vendor\\magento\\framework\\View\\Result\\PageFactory.php:56]\n#10 Magento\\Framework\\View\\Result\\PageFactory->create(true) called at [vendor\\magento\\framework\\App\\View.php:74]\n#11 Magento\\Framework\\App\\View->__construct(&Magento\\Framework\\View\\Layout\\Interceptor#0000000035329701000000000a010465#, &Magento\\Framework\\App\\Request\\Http#00000000353295f0000000000a010465#, &Magento\\Framework\\App\\Response\\Http\\Interceptor#000000003532958d000000000a010465#, &Magento\\Framework\\Config\\Scope#0000000035329540000000000a010465#, &Magento\\Framework\\Event\\Manager\\Proxy#0000000035329442000000000a010465#, &Magento\\Framework\\View\\Result\\PageFactory#0000000035329718000000000a010465#, &Magento\\Framework\\App\\ActionFlag#00000000353294ac000000000a010465#) called at [vendor\\magento\\framework\\ObjectManager\\Factory\\AbstractFactory.php:121]\n#12 Magento\\Framework\\ObjectManager\\Factory\\AbstractFactory->createObject('Magento\\Framewor...', array(&Magento\\Framework\\View\\Layout\\Interceptor#0000000035329701000000000a010465#, &Magento\\Framework\\App\\Request\\Http#00000000353295f0000000000a010465#, &Magento\\Framework\\App\\Response\\Http\\Interceptor#000000003532958d000000000a010465#, &Magento\\Framework\\Config\\Scope#0000000035329540000000000a010465#, &Magento\\Framework\\Event\\Manager\\Proxy#0000000035329442000000000a010465#, &Magento\\Framework\\View\\Result\\PageFactory#0000000035329718000000000a010465#, &Magento\\Framework\\App\\ActionFlag#00000000353294ac000000000a010465#)) called at [vendor\\magento\\framework\\ObjectManager\\Factory\\Dynamic\\Developer.php:66]\n#13 Magento\\Framework\\ObjectManager\\Factory\\Dynamic\\Developer->create('Magento\\Framewor...') called at [vendor\\magento\\framework\\ObjectManager\\ObjectManager.php:70]\n#14 Magento\\Framework\\ObjectManager\\ObjectManager->get('Magento\\Framewor...') called at [vendor\\magento\\framework\\ObjectManager\\Factory\\AbstractFactory.php:167]\n#15 Magento\\Framework\\ObjectManager\\Factory\\AbstractFactory->resolveArgument(array('instance' => 'Magento\\Framewor...'), 'Magento\\Framewor...', NULL, 'view', 'Magento\\Backend\\...') called at [vendor\\magento\\framework\\ObjectManager\\Factory\\AbstractFactory.php:273]\n#16 Magento\\Framework\\ObjectManager\\Factory\\AbstractFactory->getResolvedArgument('Magento\\Backend\\...', array('view', 'Magento\\Framewor...', true, NULL, false), array('helper' => array('instance' => 'Magento\\Backend\\...'))) called at [vendor\\magento\\framework\\ObjectManager\\Factory\\AbstractFactory.php:236]\n#17 Magento\\Framework\\ObjectManager\\Factory\\AbstractFactory->resolveArgumentsInRuntime('Magento\\Backend\\...', array(array('request', 'Magento\\Framewor...', true, NULL, false), array('response', 'Magento\\Framewor...', true, NULL, false), array('objectManager', 'Magento\\Framewor...', true, NULL, false), array('eventManager', 'Magento\\Framewor...', true, NULL, false), array('url', 'Magento\\Framewor...', true, NULL, false), array('redirect', 'Magento\\Framewor...', true, NULL, false), array('actionFlag', 'Magento\\Framewor...', true, NULL, false), array('view', 'Magento\\Framewor...', true, NULL, false), array('messageManager', 'Magento\\Framewor...', true, NULL, false), array('resultRedirectFa...', 'Magento\\Backend\\...', true, NULL, false), array('resultFactory', 'Magento\\Framewor...', true, NULL, false), array('session', 'Magento\\Backend\\...', true, NULL, false), array('authorization', 'Magento\\Framewor...', true, NULL, false), array('auth', 'Magento\\Backend\\...', true, NULL, false), array('helper', 'Magento\\Backend\\...', true, NULL, false), array('backendUrl', 'Magento\\Backend\\...', true, NULL, false), array('formKeyValidator', 'Magento\\Framewor...', true, NULL, false), array('localeResolver', 'Magento\\Framewor...', true, NULL, false), array('canUseBaseUrl', NULL, false, false, false)), array('helper' => array('instance' => 'Magento\\Backend\\...'))) called at [vendor\\magento\\framework\\ObjectManager\\Factory\\Dynamic\\Developer.php:34]\n#18 Magento\\Framework\\ObjectManager\\Factory\\Dynamic\\Developer->_resolveArguments('Magento\\Backend\\...', array(array('request', 'Magento\\Framewor...', true, NULL, false), array('response', 'Magento\\Framewor...', true, NULL, false), array('objectManager', 'Magento\\Framewor...', true, NULL, false), array('eventManager', 'Magento\\Framewor...', true, NULL, false), array('url', 'Magento\\Framewor...', true, NULL, false), array('redirect', 'Magento\\Framewor...', true, NULL, false), array('actionFlag', 'Magento\\Framewor...', true, NULL, false), array('view', 'Magento\\Framewor...', true, NULL, false), array('messageManager', 'Magento\\Framewor...', true, NULL, false), array('resultRedirectFa...', 'Magento\\Backend\\...', true, NULL, false), array('resultFactory', 'Magento\\Framewor...', true, NULL, false), array('session', 'Magento\\Backend\\...', true, NULL, false), array('authorization', 'Magento\\Framewor...', true, NULL, false), array('auth', 'Magento\\Backend\\...', true, NULL, false), array('helper', 'Magento\\Backend\\...', true, NULL, false), array('backendUrl', 'Magento\\Backend\\...', true, NULL, false), array('formKeyValidator', 'Magento\\Framewor...', true, NULL, false), array('localeResolver', 'Magento\\Framewor...', true, NULL, false), array('canUseBaseUrl', NULL, false, false, false)), array('helper' => array('instance' => 'Magento\\Backend\\...'))) called at [vendor\\magento\\framework\\ObjectManager\\Factory\\Dynamic\\Developer.php:59]\n#19 Magento\\Framework\\ObjectManager\\Factory\\Dynamic\\Developer->create('Magento\\Backend\\...') called at [vendor\\magento\\framework\\ObjectManager\\ObjectManager.php:70]\n#20 Magento\\Framework\\ObjectManager\\ObjectManager->get('Magento\\Backend\\...') called at [vendor\\magento\\framework\\ObjectManager\\Factory\\AbstractFactory.php:167]\n#21 Magento\\Framework\\ObjectManager\\Factory\\AbstractFactory->resolveArgument(array('instance' => 'Magento\\Backend\\...'), 'Magento\\Backend\\...', NULL, 'context', 'Magento\\Backend\\...') called at [vendor\\magento\\framework\\ObjectManager\\Factory\\AbstractFactory.php:273]\n#22 Magento\\Framework\\ObjectManager\\Factory\\AbstractFactory->getResolvedArgument('Magento\\Backend\\...', array('context', 'Magento\\Backend\\...', true, NULL, false), array()) called at [vendor\\magento\\framework\\ObjectManager\\Factory\\AbstractFactory.php:236]\n#23 Magento\\Framework\\ObjectManager\\Factory\\AbstractFactory->resolveArgumentsInRuntime('Magento\\Backend\\...', array(array('context', 'Magento\\Backend\\...', true, NULL, false)), array()) called at [vendor\\magento\\framework\\ObjectManager\\Factory\\Dynamic\\Developer.php:34]\n#24 Magento\\Framework\\ObjectManager\\Factory\\Dynamic\\Developer->_resolveArguments('Magento\\Backend\\...', array(array('context', 'Magento\\Backend\\...', true, NULL, false)), array()) called at [vendor\\magento\\framework\\ObjectManager\\Factory\\Dynamic\\Developer.php:59]\n#25 Magento\\Framework\\ObjectManager\\Factory\\Dynamic\\Developer->create('Magento\\Backend\\...', array()) called at [vendor\\magento\\framework\\ObjectManager\\ObjectManager.php:56]\n#26 Magento\\Framework\\ObjectManager\\ObjectManager->create('Magento\\Backend\\...') called at [vendor\\magento\\framework\\App\\ActionFactory.php:44]\n#27 Magento\\Framework\\App\\ActionFactory->create('Magento\\Backend\\...') called at [vendor\\magento\\framework\\App\\Router\\Base.php:306]\n#28 Magento\\Framework\\App\\Router\\Base->matchAction(&Magento\\Framework\\App\\Request\\Http#00000000353295f0000000000a010465#, array('areaFrontName' => 'admin', 'moduleFrontName' => NULL, 'actionPath' => NULL, 'actionName' => NULL)) called at [vendor\\magento\\framework\\App\\Router\\Base.php:167]\n#29 Magento\\Framework\\App\\Router\\Base->match(&Magento\\Framework\\App\\Request\\Http#00000000353295f0000000000a010465#) called at [vendor\\magento\\framework\\App\\FrontController.php:95]\n#30 Magento\\Framework\\App\\FrontController->dispatch(&Magento\\Framework\\App\\Request\\Http#00000000353295f0000000000a010465#) called at [vendor\\magento\\framework\\Interception\\Interceptor.php:58]\n#31 Magento\\Framework\\App\\FrontController\\Interceptor->___callParent('dispatch', array(&Magento\\Framework\\App\\Request\\Http#00000000353295f0000000000a010465#)) called at [vendor\\magento\\framework\\Interception\\Interceptor.php:138]\n#32 Magento\\Framework\\App\\FrontController\\Interceptor->Magento\\Framework\\Interception\\{closure}(&Magento\\Framework\\App\\Request\\Http#00000000353295f0000000000a010465#) called at [vendor\\magento\\framework\\Interception\\Interceptor.php:153]\n#33 Magento\\Framework\\App\\FrontController\\Interceptor->___callPlugins('dispatch', array(&Magento\\Framework\\App\\Request\\Http#00000000353295f0000000000a010465#), array(array('default_store_se...', 'page_cache_from_...', 'storeCookieValid...', 'install', 'configHash'))) called at [generated\\code\\Magento\\Framework\\App\\FrontController\\Interceptor.php:26]\n#34 Magento\\Framework\\App\\FrontController\\Interceptor->dispatch(&Magento\\Framework\\App\\Request\\Http#00000000353295f0000000000a010465#) called at [vendor\\magento\\framework\\App\\Http.php:116]\n#35 Magento\\Framework\\App\\Http->launch() called at [generated\\code\\Magento\\Framework\\App\\Http\\Interceptor.php:24]\n#36 Magento\\Framework\\App\\Http\\Interceptor->launch() called at [vendor\\magento\\framework\\App\\Bootstrap.php:261]\n#37 Magento\\Framework\\App\\Bootstrap->run(&Magento\\Framework\\App\\Http\\Interceptor#0000000035329582000000000a010465#) called at [index.php:39]\n","url":"\/magento2\/admin\/","script_name":"\/magento2\/index.php","report_id":"9d9c0469f1359f85a37614c767d6632faf6ba74053a8167e866c523e5520e11a"}
Here's a print of my console:
https://imgur.com/oHxu3Lo
If there's something else that I can provide that help you guys to help me troubleshoot this, let me know please!
Thanks in advance to the Magento Community! 