[Paul Fenn]

Hi,
I felt I had to subscribe and write my first post on this site as I was tearing my hair out with this same problem, and I don’t have that much hair left to tear out!

I had exported an .srt file, created in premiere six months before but in the meantime had somehow deleted the subtitle file in the premiere project and so needed to re-import the exported .srt file into premiere and use it again in the project timeline.
My problem was the same as the OP: the imported .srt file was reading in premiere upon import as shorter than it should have been. By importing the original video and .srt file into youtube I could see that the subtitle file was the correct length with all the subtitles in the right place so I reasoned that there must have been a fault in the .srt file.

My solution was to open the .srt file outside of premiere in a text editor, I used BBedit.
This will show you the separate subtitles as one or two lines of text with the appropriate time code of when the text should be displayed. Between each subtitle and timecode description there is a single line space gap.
I looked at the timecode of the cut-off subtitle, (the point where the .srt file wrongly ended when imported into premiere and noticed that, unlike all the other subtitles, that there was a double line gap before the next subtitle. I deleted this extra line space so that there was only one single line space between the subtitles, matching the format of all the others and saved the document. It then imported into premiere and hey presto was the correct length with all the missing subtitles back!

So it seems that premiere can export a .srt file with a line space error that prevents it from correctly re-importing but doesn’t seem to affect the .srt file when imported into youtube etc.

Hope this helps and you can hold onto your hair a little longer too!