MSNBC was forced to retract a story  reported by host Lawrence O’Donnell with a single-source, uncorroborated report that President Trump had loans co-signed by Russian oligarchs.
“Last night I made an error in judgment by reporting an item about the president’s finances that didn’t go through our rigorous verification and standards process,” O’Donnell tweeted. “I shouldn’t have reported it and I was wrong to discuss it on the air. I will address the issue on my show tonight.”
Last night I made an error in judgment by reporting an item about the president’s finances that didn’t go through our rigorous verification and standards process. I shouldn’t have reported it and I was wrong to discuss it on the air. I will address the issue on my show tonight.
— Lawrence O'Donnell (@Lawrence) August 28, 2019 
The retraction came after Charles Harder, a lawyer for President Trump, reportedly demanded an apology and retraction from NBCU for “false and defamatory statements.”
Just in: Attorney for @realDonaldTrump  sends demand for retraction, corrctn, and apology to @nbc  over segment of @Lawrence  program last nite in which he said “Russian oligarchs” co-signed Deutsche Bank loans to Trump. Letter says that statement is “false and defamatory.” Letter: pic.twitter.com/HY0ZRAES5i 
— Paul Farhi (@farhip) August 28, 2019 
Trump blasted the erroneous reporting on Twitter. He tweeted: “Crazy Lawrence O’Donnell, who has been calling me wrong from even before I announced my run for the Presidency, even being previously forced by NBC to apologize, which he did while crying, for things he said about me & The Apprentice, was again forced to apologize, this time for the most ridiculous claim of all, that Russia, Russia, Russia, or Russian oligarchs, co-signed loan documents for me, a guarantee. Totally false, as is virtually everything else he, and much of the rest of the LameStream Media, has said about me for years. ALL APOLOGIZE!”
The totally inaccurate reporting by Lawrence O’Donnell, for which he has been forced by NBC to apologize, is NO DIFFERENT than the horrible, corrupt and fraudulent Fake News that I (and many millions of GREAT supporters) have had to put up with for years. So bad for the USA!
— Donald J. Trump (@realDonaldTrump) August 29, 2019 
White House Press Secretary Stephanie Grisham explained in an interview with Fox News  why this type of reporting erodes trust in the media among voters.
“This is one of the reasons that a majority of Americans have lost trust in the media,” Grisham told Fox News. “Instead of applying ethics and standards to their reporting, journalists and left-wing outlets have weaponized the media, using it to attack and harass people with little to no regard for the truth.”