Why are strange lines appearing after my 2/4 time signature and why do they keep duplicating whenever I make a change?

So my question is, in my Symphony of the Seas composition, about halfway into the piece these strange lines that look like regular barlines keep appearing whenever I load the piece. Whenever I make a change of any sort to the piece, the lines duplicate and/or multiply, making the run-time slower because the program thinks that there are more notes being added. Sometimes my progress is even deleted, even though I save it. Please hepp mehh....