Dear Martin,
thank you for reporting this. I confirm two issues - will address it in the next release:
- the mask value is limited to 32 bits only
- masked-write of 64bit variable is rejected
Reading a 64bit variable, shifting it and masking with a mask value limited to 32bits should work without issues.
As a workaround, you can define two helper 4-byte variables with an addresses "symbol" and "symbol+4" - and access them separately.
Regards,
Michal