I have reasons to believe my employer lost my employee file and/or at least some relevant forms in the file. If the employer loses my employee file, can I sue for damages? Are they responsible in any way for losing it?

What damages have been done towards you? Why do you thin they've lost it anyway?

The employee files belong to the employer. I've never gotten my files from any employer I've ever worked for.

What damages would you sue for?

Two in a row right on the money, you have to sustain damages. This file is about you, it is not your property, you have no standing

If for example, they contained info about a TB test or phsycial, and you had to get them redid, they would have to pay for them.

If they contained proof of taking some certification courses, the cost of replacing them would be on them but then it is their file, and they can normally rebuild most of the info.