I have had the following recur several times:
I have a well-tested, often played module that runs with no problems.
I edit the module and save as a new version in a new filename. It tests and plays just fine. Call it version 1.1.
I edit some more, save under a new version in a new filename. It tests and plays just fine. Call it version 1.2.
I do this a couple of times and eventually reach version 1.5 all in new files. Attempting to run version 1.5 results in a spinning blue ring that never ends. No errors. Nothing. Windows Task Manager shows that Java (and Vassal) is using zero CPU cycles. Error log shows something like:
C:\Users\hth9\Vassal Modules\TSWW - Vassal Modules\TSWW ETO-MTO 39-43\TSWW ETO-MTO 39-43 v0.1.vmod C:\Users\hth9\AppData\Roaming\VASSAL\tiles\489644e7915916eaaf32a26253da1aa588944e6e 256 256
The tile folder name varies (as it should) but the above log entry always ends in 256 256. All the various folders under the tiles folder were created but are empty.
Now here is the very strange part:
Ok, I must have done something terrible. I go back to version 1.4 that tested and played fine. No go. Same problem.
I go back to version 1.3 – same problem. Same with 1.2 and 1.1.
None of the previous versions that tested and played fine will now even load.
I have tried rebooting and uninstalling/reinstalling Vassal. No go. Nothing that previously ran will load. It never begins tiling. I can understand some problem that prevents tiling. But how could the versions that previously ran fine possibly change? They reside in their own file.
Windows 10. Vassal 3.2.17. Java