Backend: handle null response from Eth server #3977

Job	Run time
macOS--mono-only	5m 40s
macOS--mono-only	5m 40s
linux22-github--dotnet-and-mono	3m 56s
linux22-github--dotnet-and-mono	3m 56s
linux22-github--dotnet-and-newmono	4m 44s
linux22-github--dotnet-and-newmono	4m 44s
linux22-vanilla--stockdotnet6-only	5m 12s
linux22-vanilla--stockdotnet6-only	5m 12s
linux22-vanilla--stockmono-only	5m 32s
linux22-vanilla--stockmono-only	5m 32s
macOS--dotnet6-and-mono	2m 43s
macOS--dotnet6-and-mono	16s
macOS--dotnet6-only	8m 28s
macOS--dotnet6-only	8m 28s
windows--dotnet6-and-legacyFramework	5m 12s
windows--dotnet6-and-legacyFramework	5m 12s
windows--dotnet6-only	6m 17s
windows--dotnet6-only	6m 17s
windows--legacyFramework-only	9m 17s
windows--legacyFramework-only	9m 17s
linux20-github--dotnet-and-mono	4m 14s
linux20-github--dotnet-and-mono	4m 14s
linux20-github--dotnet-and-newmono	4m 14s
linux20-github--dotnet-and-newmono	4m 14s
linux20-vanilla--newmono-only	6m 40s
linux20-vanilla--newmono-only	6m 40s
linux20-vanilla--stockmono-only	6m 0s
linux20-vanilla--stockmono-only	6m 0s
linux22-vanilla--newmono-only	6m 44s
linux22-vanilla--newmono-only	6m 44s
linux22-vanilla--stockdotnet6-and-newmono	6m 2s
linux22-vanilla--stockdotnet6-and-newmono	6m 2s
linux22-vanilla--stockdotnet6-and-stockmono	5m 8s
linux22-vanilla--stockdotnet6-and-stockmono	5m 8s
conventions	0s
conventions	0s
snap_pkg	0s
snap_pkg	0s
	3h 9m 39s

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