It looks like this is a web page, not a feed. I looked for a feed associated with this page, but couldn't find one. Please enter the address of your feed to validate.

Source: https://mit-edu-1237865049-gov.caltech-edu.pp.ua/post/1237865049

  1. <!DOCTYPE html><html lang="en-US"><head><title>Just a moment...</title><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><meta http-equiv="X-UA-Compatible" content="IE=Edge"><meta name="robots" content="noindex,nofollow"><meta name="viewport" content="width=device-width,initial-scale=1"><style>*{box-sizing:border-box;margin:0;padding:0}html{line-height:1.15;-webkit-text-size-adjust:100%;color:#313131;font-family:system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,"Noto Sans",sans-serif,"Apple Color Emoji","Segoe UI Emoji","Segoe UI Symbol","Noto Color Emoji"}body{display:flex;flex-direction:column;height:100vh;min-height:100vh}.main-content{margin:8rem auto;padding-left:1.5rem;max-width:60rem}@media (width <= 720px){.main-content{margin-top:4rem}}.h2{line-height:2.25rem;font-size:1.5rem;font-weight:500}@media (width <= 720px){.h2{line-height:1.5rem;font-size:1.25rem}}#challenge-error-text{background-image:url("data:image/svg+xml;base64,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");background-repeat:no-repeat;background-size:contain;padding-left:34px}@media (prefers-color-scheme: dark){body{background-color:#222;color:#d9d9d9}}</style><meta http-equiv="refresh" content="360"></head><body><div class="main-wrapper" role="main"><div class="main-content"><noscript><div class="h2"><span id="challenge-error-text">Enable JavaScript and cookies to continue</span></div></noscript></div></div><script>(function(){window._cf_chl_opt = {cvId: '3',cZone: 'mit-edu-1237865049-gov.caltech-edu.pp.ua',cType: 'managed',cRay: '95fd23b7ff35c946',cH: '9BNq6N5wVWLS6l.UK0zTqfZZUghk8Ds9Wb3jnHLOb1w-1752623189-1.2.1.1-VpIhip6FvZcbMdvzj.9PQIQuvgeNIJsiTV_jRsDCxQ3ek5Ybr.QDgBbyKOV0Tce3',cUPMDTk:"\/post\/1237865049?__cf_chl_tk=pJgf51mN._NzjMC7sBjhmRiTb_jzudDlZ7MflRr3qVM-1752623189-1.0.1.1-d4InIFaPM9qpyyE_i26DpfL2fa6gxa.RTYbSBMjjdv4",cFPWv: 'g',cITimeS: '1752623189',cTplC:0,cTplV:5,cTplB: 'cf',fa:"\/post\/1237865049?__cf_chl_f_tk=pJgf51mN._NzjMC7sBjhmRiTb_jzudDlZ7MflRr3qVM-1752623189-1.0.1.1-d4InIFaPM9qpyyE_i26DpfL2fa6gxa.RTYbSBMjjdv4",md: 'm6D_HU4txZ1_gsx9M3NdtQopeV0rt..mlBPAhwU285g-1752623189-1.2.1.1-Hm39BVqyxeUKcS6kGovsngBWgirbD1qgDbgpqSu15a4zzdw.kciKWh5hCgfnXX8rQiruixTIrLUzsrr9OsFOfHOq7NEREk8XpCFWxC1fxb58eSjeBvJdJwrQG8A7wMEYkko0M8vCffpI4QBxYjEFWsGwfhtD_J8SmN_FSQR0_5LKqE.uSSZyochMdcQNWSQfF8oqUvbi5o9Q8Z6sBVLjPtkEjvQUdiugIGtsjjEBtprbBAItBYiQydGLw7VlG.euEd9DDKyN3Qp6akO6z8oEpsJsTTCMkoQWgAjIf1KUl4jo8pzR5XV5ypT0vJSuE.WkFBiGKuhN6E7S3oNAFJlbWNPw6vmSGkzslbfqczlPsz2a53cfZIIFfTtTXlDNTFd.vjB.icYq_gxjPV76sa4OtBrl9lLb5Jv7snfi5sAAeKIfeKOHw0HqFT2aypRJDMWNcScJ3vM37xJK89Rnbp4oWOuw5xV.yf1b3YMWzbSxlMxzYSCjglzrMKkWuyGiWwudaBRfwRva2XRNXSgjqS8D4BGdiGtEvWMpiAYMyd0kFcUyOMfW.fA.qdot_T5f0OBfgH31FcbAh.izEXwdq5cFnJs8VGI5IW4FQGfzSjBnpHMCpKWPWkbNWsiguxJuSazzZ3NhFOXii.QCFAZuBx_mdf3ezpeY0PJhIxbI8PBjMWZDG0WCzCjcj72UDBTq2jzLzO9tOwxbhMPc5LxbVttdMO9n4zWZdCqDM7E5RDMBIB6DqZD1jsZR4X_Ga.DGUKT1MFhd9C.QLwTVRosinpbnYxNflorA75S8MO1z_mdeRMyOoh.5veSvM_v7pa.YMvz0fAvcsTCElY25sEtl__OGin9kwE6QfN8.wfWPdbIhtco',mdrd: 'cWCCZRoIZ0pcBobrO.J4RL04h38kOh2UrAvf.wlDEx8-1752623189-1.2.1.1-y.nihtiYa6ac7C8gb3CWbilIgreAB2QEgN41qEduPS5Io_rM6v9vHxV4UIpEKNeqK72lQ8xX2KF3WE2eRBw2RjzbgWTaD3sFyvYya3VG6SyqSUdZA7x_h6ivBK26a8CdbfiwFbnSAh843jQRriYT_qrVABaNskvBSDErhTAzUlzu8dim6nBCI1SDPj2p_kQuxmcLJYIw4lSOm4Ni.YAEGoVpAJWutd9cVCwORBSTB5tHsmri8PqX6dJyWVCW9gE.mgwb5Hkpt6GBGaghWwHAZfVRWXNLVF7SUDleEW3jce8mmoU7xRN9aqF8MnthrzRW7cT7IQvuhm4_Yhk9Gfu2Tz9cdv9lUYWqudAH810ITUn6Pz5JehK14nBk2zTjfS3xu2_QBDYYFcla7MmE99UMf50MwWr769SFLCMm7nhpS5zd7wtShM.m5JG5fT3tHUtl54HLNpEWz0kofz0e11juyowlR_b.K3Ewc.tEPob9k_mrXEFYAuhr4tWYGPAlErlTPjO8Jjf6suYI7154XbhriEhFh74MTTMSACxqp6_v5UO6q27hIOZgDRr1vexIDwQ5BUeZO6DqNGLhHZarFLiZq5JTIszGMzKDzUtqVA.2PDfiJBvGvko6qyvzPtes6FZsqxTYw7oo3QdOmd_Crbmjm4ngklahfi9mQmywCQ.zxBPeArUzk0IirVJkLsBojv8N1SgiffVToenJdd1jFkz934HZNdLhjjHRv5FKOmooCQfDVHyNNVapJxFofs4JjrAe5HJ8_C10R4uoKaEyRqDLPckfHcG7bxfEIRyYG4kGwbQGpY98951Cj31Z.tS9KDSAOwW_IXhTpF31tX5fure.Bqkt7EdlgHcFz1dBifr06ZuUwdWZynsXy1Z9cvb.X8n.OND4Ti8LYRJpxIszOXmboLum4VpprDp5XpDPxvgjZjz6NkLBRsKqF90QDmYge_n3JeKe2GgDocrQ9V3usUsfbl_Ka8G1z9kgX15kU8Gjgpk9ekthPj1av.G6TWU8mCKyCTdcJTsSMLObI_Zecr9fqzmmYD3zGprraHaLpk3F.NqeCA1yeUP1wRPTIDAtj6FvbP_YZAKLn6_0wakPpeqs1YhxiXLm.Gi_8iZxDsdm94LNcjUf_lXxT2cr_mhguOkyBBD43yyV09_07txPQgjca5In09qSKvdjYHkxFN79ejU5tvu6atYfPa8A.02avzJwLIfB630c9hMOXWdXrIj5vboMg5t6MhUR_TmrnjEzg.T5QuRP.25pRQGZ.4MVLTWWM3g9uIvf8CA9RilRq1tnhLubWlohjiFjCBI8TAqlVMWJB3xm2_NR_PyWIzc.VibePK4nDJ2iUv42GF89FuEiCA9zWSDGvPZ.V2_3hkHhuw6ZPIbQMnq.9lyO10TemZSoAyYuNmBzEXObxGHL5oon6y6v2rNOgSfeGl9GLoCfHSve6AkU8V7wyh4l46Wei31xHdKTw6gvF19FCyEimX5Ko45K29Pi2.evcHPuqYOJxGVP78DziaZ9IerZJRx1Ncb.5mDPnaocDLZJLIxRKoPjOsmUGiXzdbMimDVHBmBKyuEyLw8VKVxTVCx0j8akdUw4dBOg4gGR3oLUfzlV.zf7ppU.RogwkIm7NFo0AgaHQcVewlLaJ79E1dZYkvE4XabeC8d3nexdeNdfgPQ2O7IzrZlrv8sf22kVw_OIniIGUe8.sdxVEjWujMrMiZRI7mLr.rhelayYQvDXkoea28dybd3i4L8HMQoz05tXrij3pvsJivhOKC2hBHDYzo3.BCY56K9Nxz8SQS6uD6_6xSYKh8vSUm2bNzRdpi_MAdaO_Fic.q0aeQzaYmoDYvVHrDEr3wP.L_tDzC5VoYvryXLZMUAoWXSDK_xVIlnHd7HbrYGlcPcRo5vKATjYQ9Z.xTP8',};var a = document.createElement('script');a.src = '/cdn-cgi/challenge-platform/h/g/orchestrate/chl_page/v1?ray=95fd23b7ff35c946';window._cf_chl_opt.cOgUHash = location.hash === '' && location.href.indexOf('#') !== -1 ? '#' : location.hash;window._cf_chl_opt.cOgUQuery = location.search === '' && location.href.slice(0, location.href.length - window._cf_chl_opt.cOgUHash.length).indexOf('?') !== -1 ? '?' : location.search;if (window.history && window.history.replaceState) {var ogU = location.pathname + window._cf_chl_opt.cOgUQuery + window._cf_chl_opt.cOgUHash;history.replaceState(null, null,"\/post\/1237865049?__cf_chl_rt_tk=pJgf51mN._NzjMC7sBjhmRiTb_jzudDlZ7MflRr3qVM-1752623189-1.0.1.1-d4InIFaPM9qpyyE_i26DpfL2fa6gxa.RTYbSBMjjdv4"+ window._cf_chl_opt.cOgUHash);a.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(a);}());</script></body></html>
Copyright © 2002-9 Sam Ruby, Mark Pilgrim, Joseph Walton, and Phil Ringnalda