I tried using the transmogrify script which works nicely from the command line as a servlet, and you can see someone is not properly encoding and decoding parameters:
https://cottagesystems.com/AutoplotServlet/ScriptGUIServlet?arg_1=pj%28%5Cd%2B%29_%28.%2B%29_%28n%7Cs%29.%28dat%29&arg_2=%241+%242+%243&arg_3=pj1_5_n.dat&script=https%3A%2F%2Fgithub.com%2Fautoplot%2Fdev%2Fblob%2Fmaster%2Fdemos%2F2021%2F20210108%2Ftransmogrify.jy
Also the label "Transmogrify" is not used.
It looks like it might load fine initially, and then the second use fails.
Also the label "Transmogrify" is not used.
It looks like it might load fine initially, and then the second use fails.