Third Party PHOTON: RPC's thinking a string[] with only one string IS that string!

if an RPC has as a string[] parameter (variable length array) and the string[] parameter used when calling it has exactly one element... then the RPC will NOT recognize it as a string array... and thinks it must use an NPC with a 'string' parameter in that place instead... (i.e... not a string array but just a single string)...
.
if the string[] parameter has 2 or more elements it recognizes the parameter just fine... only when it has exactly one element is this a problem... i have not yet tested the zero-element string array or null cases...
.
this is obviously a bug... i can't see how this could possibly be a working-as-intended feature... a bug which has not been fixed in many years...

and yes... i know this belongs more in a PHOTON forum... and Unity is not the cause (i don't think)... but i feel mentioning this 'quirk' belongs here too... since it can be the source of a lot of heartache...

 

I think you need to work around this by explicitly passing an object[] to the parameters of the RPC method.
Along these lines: new object[] { string[] yourStringArrayWithOneItem }.
The quirk is (afaik) in our use of params object[] parameters as last parameter. It does not "get" your string[] is meant to be the first entry in the object[], instead of being the parameters array.