PDF plug-in fails to show online PDF files, but can show local PDF files

I am using Firefox Portable ESR 52.4.1 32-bit, with SumatraPDF plug-in.

Several days ago, Firefox Portable crashed and popped-up a windows asking me either to send troubleshoot info Mozilla or not, and to select "restart" or "exit". This type of crash happens regularly because I have 100+ extensions and my Zotero profile is larger than 5GB so I'm already familiar with it, and every time it happened before, I selected "exit" because I'm running Firefox Portable with "AllowMultipleInstances=true". But several days ago when it crashed again, I mistakenly clicked "restart" after Firefox Portable crashed and popped up the window. Then after it restarted, I closed Firefox and restarted it from the PortableApps.com menu, then, the SumatraPDF plug-in failed to open any online PDF files, i.e., any URL containing a PDF (e.g., http://www.pdf995.com/samples/pdf.pdf), but it can open local PDF files without problem (e.g., file:///Z:/PortableApps/pdf.pdf).

I've tried renaming the pluginreg.dat and mimeTypes.rdf, but problem persisted.

I tried other PDF plug-in, but it has the same problem.

It looks like after I clicked the "restart" following Firefox's crash, something related to or opened by "plugin-container.exe" was corrupted, but what were corrupted exactly and how to fix it?

Using Firefox's built-in PDF viewer is NOT a solution to me, because it simply lacks of too many functionalities that I must have. Resetting profile is NOT an option, since I have 100+ extensions and >5GB zotero profile. This is why I'm still using Firefox Portable ESR 32-bit.