Nonsense and complete hoax. There is no confirmation in official US Shuttle mission reports and Department Of State records and in any other US sources. There was no such accident and no "diplomatic protest". I’ve tracked the matter VERY CAREFULLY over many sources and records. I’ve tracked also how this stupid information started to exist in Internet. First this information was placed in Jane’s Defence website edited by Steven Zaloga about 1995. That's what Mr Zaloga said on this information: 
 "This is a Soviet claim, not from the US side. It is cited in the memoirs of 
 a senior PVO-Strany officer (Col.Gen. Yuri Vointintsev) who wrote one of the 
 better series of articles on their strategic defense program in 
 Voenno-istorichesskiy zhurnal "Neizvestniye voiska ischeznuvshei 
 sverkhderzhavy" (No. 11, 1993, p. 17) during a period of relative openess 
 (as compared to today). Though whether it's true or not, I am not certain. I would be 
 curious to learn if you discover more about it. 
 Cheers! 
 Steve Zaloga"  
 So, short and clear. 
 Everyone on other websites cites exactly text from english Wikipedia article concerning STS 41G mission. The source cited in Wikipedia is an article by Lieutenant Colonel Boris Kononenko (June 1996). "Federation of American Scientists - "Silent Space Is Being Monitored. I’ve read the article and got to know that Kononenko cites also memoirs of... Yuri Vointintsev:) So, Yuri Vointintsev is the original, first and the only source of this information. Very, very unreliable source. Why? First Soviet Union and its officials were known very well because of telling ordinary  lies and a lot of propaganda. Next let’s analyze his memoirs: 
 
 "In those days I was preparing a detailed report for the Minister of Defense on means being used to track the Shuttle flight and on results of Outer Space Monitoring System operation. Then, some time in the autumn of 1983, Marshal of the Soviet Union D. Ustinov called me on the Kremlin phone [kremlevka]: I have before me your report on work on the Shuttle. Tell me, why hasn't the experimental laser complex of General Designer Nikolay Ustinov been used?' Dmitriy Fedorovich was excited over his son's creation. At that time a team of 300 specialists was performing modifications on the complex, and I reported this to the Minister of Defense. And the experiment took place on 10 October 1984, during the Challenger's 13th flight, when its orbital revolutions were passing in the vicinity of the National Air Defense Troops state range near Lake Balkhash,” 

 Well, a little explanationJ Nikolay Ustinov was a son of Dimitriy Ustinov Soviet marshal and Ministry of Defence. He was General Designer at Sary Shagan complex because of his father rather then his engineering skills. Probably he lied a lot to father on laser facilities and its  power. Dimitriy ordered to fire uncompleted and not working son’s laser  so what could they do?? In Soviet reality they risked degradation, prison even death! Knowing USSR “standards” probably they simulated test and reported to marshal Ustinov that everything went well. After Ustinov senior death his son was simple fired very quickly. 

 "The Challenger crew later reported that as they were flying over the vicinity of Balkhash, communications on the craft suddenly shut down, malfunctions appeared in operation of gear, and the astronauts themselves did not feel quite well. The Americans began to investigate and soon realized that the crew had been subjected to some kind of artificial effect from our sideand lodged an official protest with the USSR. Based on humane considerations, the laser unit as well as a portion of the range's radiotechnical complexes having a high energy potential subsequently were not employed to track the Shuttles." 

 Ordinary lies! there were no such events reported in STS-41G mission reports nor in other NASA documents or astronauts memoirs. There is no evidence of “diplomatic protest” concerning such event in DoS records even in other US official documents. In 90s western experts visited Sary Shagan installation –its power  was much more insufficient to do something more then tracking satellites during very good weather! Even completed in late 80s it was unable to do nothing more so “not employing full power because of humane considerations” sounds extreme laughable:)   

 So, Vointintsev’s tales seems to be a mythology created to boast his work and soviet technology.   
 I thought we want to make Wikipedia a reliable source of confirmed and checked well information not to repeat old-times soviet propaganda! Placing this information as cretin knowledge is nothing more then informational abuse.