Well, I just did another clean install of TLR46a on Windows 10 (64 bit) and it works fine.
But in light of what you are seeing, it's very strange how that even works AT ALL...
Both TLR46.cmd and the dosbox-SVN_MB6.conf configuration file explicitly call "TLR46" and not "TLR46a".
But the C:\TLR\ folder only contains TLR46a.exe
And if I rename that executable to anything else (including 'TLR46.exe') then I get "Illegal command: TLR46a.exe" message from DOSBOX. (e.g. it cannot find the TLR46a.exe!)
So 'something somewhere' is actually instructing DOSBOX to run tlr46a.exe
(Maybe the installer has coded something in the registry?? ...)
I just tried editing the second-last line of TLR46.cmd to read
start "TLR46a" "%Progfolder%\DOSBox_MB6\dosbox.exe" -noconsole
AND IT WORKS FINE.
But the original cmd file written
start "TLR46" "%Progfolder%\DOSBox_MB6\dosbox.exe" -noconsole
ALSO WORKS FINE. :huh:
Here in Windows 10 64-bit, at least...
.... ah, waitaminute... :unsure:
I can edit the TLR46.cmd to call any random string, and the program still runs FINE
(example: start "ZZ" "%Progfolder%\DOSBox_MB6\dosbox.exe" -noconsole)
So, it appears that C:\TLR46\TLR46.cmd is actually not being fully parsed... the solution to your issue must lie elsewhere?