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System Error: missing icuuc55.dll


I had RIOS running on my laptop fine, and then I installed ArcGIS 10.3.1. Now when I launch RIOS I get the following error message

 " The program can't start because icuuc55.dll is missing from your computer. Try reinstalling the program to fix this problem"

I've uninstalled and reinstalled RIOS 3 times and I still get the same message. Are there any fixes for this problem?



  • jdouglassjdouglass Administrator, NatCap Staff
    Hi @Sylvie,

    Unfortunately, icuuc55.dll is not a DLL that we provide, and this is the first I've ever heard of this issue ... it looks like icuuc55.dll provides unicode support for Windows and is probably distributed with the OS.  I wonder if ArcGIS messed with some environment variables as part of its installation.  Does uninstalling ArcGIS allow RIOS to run?
  • Thanks for your reply 

    Yes, I think that it must have something to do with ArcGIS messing about with my environmental variables. Unfortunately I'm on a one-year student licence and am a bit nervous about uninstalling Arc that I won't be able to reinstall with the same licence code. I've managed to install RIOS on another computer for the moment and will use that. Again, thanks for your help!

  • jdouglassjdouglass Administrator, NatCap Staff
    Sounds good, and sure thing!
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