it is my first time here I would like some help with this error that I have help me please
`[100%] Linking CXX executable otbr
/tmp/cceBX6Bu.ltrans5.ltrans.o: In function Player::sendUnjustifiedPoints()':
<artificial>:(.text+0x83a2): undefined reference to ProtocolGame::sendUnjustifiedPoints(unsigned char const&, unsigned char const&, unsigned char const&, unsigned char const&, unsigned char const&, unsigned char const&, unsigned char const&)'
/tmp/cceBX6Bu.ltrans18.ltrans.o: In function Player::postAddNotification(Thing*, Cylinder const*, int, cylinderlink_t) [clone .constprop.853]':
<artificial>:(.text+0xb58): undefined reference to ProtocolGame::sendInventoryClientIds()'
/tmp/cceBX6Bu.ltrans30.ltrans.o: In function Player::postRemoveNotification(Thing*, Cylinder const*, int, cylinderlink_t) [clone .constprop.1061]':
<artificial>:(.text+0x91fb): undefined reference to ProtocolGame::sendInventoryClientIds()'
/tmp/cceBX6Bu.ltrans3.ltrans.o: In function Player::postAddNotification(Thing*, Cylinder const*, int, cylinderlink_t)':
<artificial>:(.text+0xb938): undefined reference to ProtocolGame::sendInventoryClientIds()'
/tmp/cceBX6Bu.ltrans3.ltrans.o: In function Player::postRemoveNotification(Thing*, Cylinder const*, int, cylinderlink_t)':
<artificial>:(.text+0xc00b): undefined reference to ProtocolGame::sendInventoryClientIds()'
/tmp/cceBX6Bu.ltrans21.ltrans.o: In function LuaScriptInterface::luaPlayerSendInventory(lua_State*)':
<artificial>:(.text+0x5028): undefined reference to ProtocolGame::sendInventoryClientIds()'
collect2: error: ld returned 1 exit status
CMakeFiles/otbr.dir/build.make:103: recipe for target 'otbr' failed
make[2]: *** [otbr] Error 1
CMakeFiles/Makefile2:127: recipe for target 'CMakeFiles/otbr.dir/all' failed
make[1]: *** [CMakeFiles/otbr.dir/all] Error 2
Makefile:83: recipe for target 'all' failed
make: *** [all] Error 2`
