Out%20of%20memory%0D%0A%0D%0AStack%20trace%3A%0D%0A%28003B2452%29%20%0D%0A%28003B2452%29%20%0D%0A%280033F3CB%29%20%0D%0A%28001DC32C%29%20%0D%0A%2800217AC5%29%20%0D%0A%280021C609%29%20%0D%0A%28001D73AC%29%20%0D%0A%280078E0D1%29%20%40%40Synchronizeprogress%

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>

WinSCP 5.7.7

Error message:
Out%20of%20memory%0D%0A%0D%0AStack%20trace%3A%0D%0A%28003B2452%29%20%0D%0A%28003B2452%29%20%0D%0A%280033F3CB%29%20%0D%0A%28001DC32C%29%20%0D%0A%2800217AC5%29%20%0D%0A%280021C609%29%20%0D%0A%28001D73AC%29%20%0D%0A%280078E0D1%29%20%40%40Synchronizeprogress%40Finalize%0D%0A%2800217700%29%20%0D%0A%28001E2563%29%20%0D%0A%280034059C%29%20%0D%0A%28000152F7%29%20USER32.dll%0D%0A%2800015D35%29%20USER32.dll%0D%0A%2800015DE3%29%20USER32.dll%0D%0A%2800015E41%29%20USER32.dll%0D%0A%280000F117%29%20ntdll.dll.KiUserCallbackDispatcher%0D%0A%28000186C0%29%20USER32.dll.SendMessageW%0D%0A%280021290C%29%20%0D%0A%28001DC02A%29%20%0D%0A%28001DC0A8%29

Status: not_matched

The problem happens rarely. I cannot reproduce it.