CS5 to CC23 file conversion

Hi Team,

Previously we are working on CS5 now i updated on the AI 23 . after that i have faced some kind of issue in  AI file creation.

These are

1. while opening the CS5 file AI images in CC23 some of the text are not visible.
2. Text boxes are shrinking in CC23.

for your reference below i pasted CS5  and CC23 image. below i highlighted what is the issue is in CC23.

this the sample images for your reference but i have an lot of text missing in my file. kindly give respective sollution  for this

CS5                                                                                         CC23

Note : important things we have crated lot of file in CS5 there is no possible things to create a new file in CC23 so kindly give the option or any methodology to accessing same file in CC23 without any missing things.