Corrupted Measures/Time Signatures

I originally started the score in 2/4. I changed the time signature for all instruments into 4/4. I realized that it was still rendered as 2/4, although displayed as 4/4. Shortly after, MuseScore crashed and ever since, when I open the score, it tells me it's corrupted. Measures past the 4/4 mark, I've had to manually and individually go into the measure settings and change the time value of the measure. Regardless, there is a gap in the measure. They only support 2/4 rhythms, but count everything as 4/4. Rests are not displayed but the bar goes over the gaps as if there are. How do I fix this ?