If you are having problem’s with importing/Rendering with jpeg files in Adobe Premiere Pro, do following things
1) Check Color Space i.e. RGB? CMYK?
If they are CMYK then change them into RGB using photoshop or other program
2) Check its bit rate.8, 16 or 32
Re-save is as 8 bit if they are 16/32 bit.
3) convert the JPEGs into PSD files which Premier Pro should handle elegantly regardless of bit depth.
4) If image size are larger then reduce image size or dynamically link to AE (AE can handle these, but premiere does not.)