Build error: subscripted value is neither array nor pointer nor vector

When I run idf.py build I am seeing the following build error:

/SOCORAD32/SCRD32_firmware_official/main/uart.c: In function 'uartChannelSetting':
/SOCORAD32/SCRD32_firmware_official/main/uart.c:104:44: error: subscripted value is neither array nor pointer nor vector
         uartTxBuf[33] = gCtcssList[gTxCtcss[0];
                                            ^
/SOCORAD32/SCRD32_firmware_official/main/uart.c:104:47: error: expected ']' before ';' token
         uartTxBuf[33] = gCtcssList[gTxCtcss[0];
                                               ^
                                               ]
/SOCORAD32/SCRD32_firmware_official/main/uart.c:105:49: error: expected ';' before '}' token
         uartTxBuf[34] = gCtcssList[gTxCtcss][1];
                                                 ^
                                                 ;
     }
     ~                                            
In file included from /SOCORAD32/SCRD32_firmware_official/main/main.h:32,
                 from /SOCORAD32/SCRD32_firmware_official/main/uart.c:1:
At top level:
/SOCORAD32/SCRD32_firmware_official/components/ssd1306/font8x8_basic.h:41:16: warning: 'font8x8_basic_tr' defined but not used [-Wunused-variable]
 static uint8_t font8x8_basic_tr[128][8] = {
                ^~~~~~~~~~~~~~~~
ninja: build stopped: subcommand failed.
ninja failed with exit code 1

MordFIdel / SOCORAD32

Build error: subscripted value is neither array nor pointer nor vector #32