Could not initialize class *ImagingConverter

[Evgeniy Smyk]

Hello, a fiew days ago i installed confluence server edition for someone test and saw, that in some pages have a error with initialize class com.atlassian.plugins.conversion.convert.image.ImagingConverter when in pages been pdf files. i started google the error, and find that i should to clear cache and re-enable some modules, whos using the convetration pfd, but it wasn't help me, can you says what i should to do? 

[Andrey Kabakov]

I had the same problem with 7.1.1, tried to update to 7.3.3 and downgrade to 7.1.x-7.3.x. I cleared plugins cache and turned off (on) modules, but I managed to resolve this issue with yum update (Centos 7.7) and server reboot. Final version 7.3.3.