Bug: StrongDMM has issues opening version 516

[CrazyAmphibian]

Version

v2.16.0.alpha

What happened?

refuses to load environment that requires 516, even though 516 is the installed version. in particular 516.1662

Reproduction

1. Run StrongDMM
2. Open enviroment or map file
3. It no compiles
4. Cry

"works on my machine"

Relevant log output

parser error: compilation errors
__DEFINES/setup.dm - [3:1] #error Your version of byond is too old, you need version 513 or higher
code/world.dm - [9:1] #error You need at least version 516 to compile

for context:

__DEFINES/setup.dm

#if DM_VERSION < 516
#error Your version of byond is too old, you need version 513 or higher
#endif


code/world.dm:

#if DM_VERSION < 516
#error You need at least version 516 to compile.
#endif

[CrazyAmphibian]

it appears that older versions can open and save 516 just fine. 2.10 works.