Build problems with platformio

[remrat]

Clean install... Getting build errors:

StaticJsonDocument<312> jsonBuffer;
^
C:/Users/Remmert/Documents/PlatformIO/Projects/gateway/src/_txRx.ino:76:50: error: 'deserializeJson' was not declared in this scope
auto error = deserializeJson(jsonBuffer, bufPtr);
^
C:/Users/Remmert/Documents/PlatformIO/Projects/gateway/src/_txRx.ino:97:45: error: expected primary-expression before '>' token
JsonObject root = jsonBuffer.to();

                                         ^

C:/Users/Remmert/Documents/PlatformIO/Projects/gateway/src/_txRx.ino:97:47: error: expected primary-expression before ')' token
JsonObject root = jsonBuffer.to();
^

[webgps]

Clean install... Getting build errors:

StaticJsonDocument<312> jsonBuffer;
^
C:/Users/Remmert/Documents/PlatformIO/Projects/gateway/src/_txRx.ino:76:50: error: 'deserializeJson' was not declared in this scope
auto error = deserializeJson(jsonBuffer, bufPtr);
^
C:/Users/Remmert/Documents/PlatformIO/Projects/gateway/src/_txRx.ino:97:45: error: expected primary-expression before '>' token
JsonObject root = jsonBuffer.to();

                                         ^

C:/Users/Remmert/Documents/PlatformIO/Projects/gateway/src/_txRx.ino:97:47: error: expected primary-expression before ')' token
JsonObject root = jsonBuffer.to();
^

Hi remrat,

What is ArduinoJson version?