After reading all the comments and seeing that in most cases the problem is in Win10, I comment.

It seems a typical problem of the program for not being able to interact with the system, when this happens, it is usually for not installing the program as administrator, or also for changes in the OS that consequently restricts access.

Therefore, I recommend you to keep the following in mind.

Install as administrator.

Execute as an administrator.

Go to the installation folder and subfolders and verify that you have write permissions, the same for:

Adobe folder in my documents.

Location of Cache Folders.

Location of project folders, source material and files

If Premiere can move freely through the system, it is very difficult to give them this error.

Someone suggested that instead of "save as", try creating a new project first and renaming that. I've just tried it and it seems to work just fine now. Then you'll be able to "Save as".

I guess the issue is related to the original "untitled" project that's opened automatically?

I just fund out disabling the NVidia card in Device manager no more crashes when Save as or import. I am going to keep digging to find a solution.
Win 10 64
Nvidia gtx1080

DP>

Hi,

A good number of people are getting the crash after performing a "Save As," then not entering a new name for the project (like incrementing it), and then press the Save As button a second time. The crash then occurs.

For those crashing in this manner, are you entering a new name for your project before attempting to Save your project? We cannot reproduce this issue otherwise.

Regards,
Kevin

Hopefully this works for you as it did for me...

Check to see how many instances of Premiere Pro are running. In my case - there were 2 exe's running int he background. After I ctrl-alt-deleted and then quit the processes everything was back to normal.

Hope this helps.

I've also been having this problems for at least 6 months now with every update. (no plug-ins).

I have a possible work-around, see my newest post, re: this problem, but other slow-down problems are introduced...

Please Adobe Fix This.

I have found solution for the same problem  .... very simple

create new project and import old one into ... now save as works fine for me ... good luck

Problem disappeared! (for now?)
I've updated to the latest version (12.0), but even after few restarts nothing happened..., but the thing about user account made me anxious, because there already been problems with account.. Not type, but name.
IT dept. manages our PC, so after a recent reinstall they made my account with diacritic letters... User "Pēteris Kārkliņš" in my case.
While Microsoft understands diacritic letters and request registration of windows in correct local language, Adobe still works in US and doesn't care about the rest of the world. They doesn't even use unicode font on their website!

Don't know if that will solve every bodies problems...

Here's how to change user name in win10:

How to change the registered name and account username in Microsoft Windows 10 - YouTube

Hi Chris,

Can you please confirm if the issue that you were facing has been resolved or not?

In case if it hasn't been fixed yet please let us know and I will be glad to assist you.

Thanks,

Kulpreet Singh