I’m having the same RTCharls’ issue.
Windows 7 Pro 64bit with Service Pack 1 - 8GB RAM - i7 2600 3.4GHz
RT5.4 is running fine.
RT 5.5rc1 (tried the “official” build, the gaaned’s build and also the Carmelo’s portable build) all builds produced an error message: “The procedure entry point ScriptIsComplex could not be located in the dynamic link library GDI32.dll.”
There is another topic with this point: RT 5.5 doesnt run on Win 7