RailControl hard-coded searches its files in the working copy. Make it load its files from the FHS compliant installation path instead.
Index: railcontrol/Server/Web/WebClient.cpp
===================================================================
--- railcontrol.orig/Server/Web/WebClient.cpp	2025-05-01 06:03:03.707240816 +0200
+++ railcontrol/Server/Web/WebClient.cpp	2025-05-01 06:03:03.707240816 +0200
@@ -747,7 +747,7 @@
 		char workingDir[128];
 		if (getcwd(workingDir, sizeof(workingDir)))
 		{
-			ss << workingDir << "/html" << virtualFile;
+			ss << "/usr/share/railcontrol/html" << virtualFile;
 		}
 		string sFile = ss.str();
 		const char* realFile = sFile.c_str();