IntelliJ Not Launching Post-Update - 'java.lang.ClassNotFoundException: com.intellij.ide.plugins.PluginManager"

After updating IntelliJ and when I tried to re-launch the program after updating, I was greeted with the error shown below. I restart my system afterwards, but IntellJ still didn't start. Help would be appreciated, especially if I don't lose my settings and projects in the process. Thank you.

Internal error. Please report to http://jb.gg/ide/critical-startup-errors

java.lang.ClassNotFoundException: com.intellij.ide.plugins.PluginManager
at com.intellij.util.lang.UrlClassLoader.findClass(UrlClassLoader.java:225)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:348)
at com.intellij.ide.Bootstrap.main(Bootstrap.java:36)
at com.intellij.idea.Main.main(Main.java:79)

EDIT: I just found the updater log files and noticed this in it, could this be the culprit?

01 Jul 2017 18:28:47 ERROR Runner.printStackTrace - C:\Program Files (x86)\JetBrains\IntelliJ IDEA 2017.1\lib\idea.jar (Access is denied)
java.io.FileNotFoundException: C:\Program Files (x86)\JetBrains\IntelliJ IDEA 2017.1\lib\idea.jar (Access is denied)
at java.io.FileOutputStream.open0(Native Method)
at java.io.FileOutputStream.open(FileOutputStream.java:270)
at java.io.FileOutputStream.<init>(FileOutputStream.java:213)
at java.io.FileOutputStream.<init>(FileOutputStream.java:162)
at com.intellij.updater.Utils.copyStreamToFile(Utils.java:198)
at com.intellij.updater.Utils.copy(Utils.java:178)
at com.intellij.updater.BaseUpdateAction.replaceUpdated(BaseUpdateAction.java:125)
at com.intellij.updater.UpdateAction.doApply(UpdateAction.java:76)
at com.intellij.updater.PatchAction.apply(PatchAction.java:201)
at com.intellij.updater.Patch.lambda$apply$2(Patch.java:332)
at com.intellij.updater.Patch.forEach(Patch.java:396)
at com.intellij.updater.Patch.apply(Patch.java:322)
at com.intellij.updater.PatchFileCreator.apply(PatchFileCreator.java:83)
at com.intellij.updater.PatchFileCreator.apply(PatchFileCreator.java:75)
at com.intellij.updater.Runner.doInstall(Runner.java:323)
at com.intellij.updater.Runner.lambda$install$0(Runner.java:290)
at com.intellij.updater.SwingUpdaterUI.lambda$doPerform$2(SwingUpdaterUI.java:194)
at java.lang.Thread.run(Thread.java:745)
01 Jul 2017 18:28:47 ERROR Runner.printStackTrace - C:\Program Files (x86)\JetBrains\IntelliJ IDEA 2017.1\lib\idea.jar (Access is denied)
java.io.FileNotFoundException: C:\Program Files (x86)\JetBrains\IntelliJ IDEA 2017.1\lib\idea.jar (Access is denied)
at java.io.FileOutputStream.open0(Native Method)
at java.io.FileOutputStream.open(FileOutputStream.java:270)
at java.io.FileOutputStream.<init>(FileOutputStream.java:213)
at java.io.FileOutputStream.<init>(FileOutputStream.java:162)
at com.intellij.updater.Utils.copyStreamToFile(Utils.java:198)
at com.intellij.updater.Utils.copy(Utils.java:178)
at com.intellij.updater.BaseUpdateAction.doRevert(BaseUpdateAction.java:132)
at com.intellij.updater.PatchAction.revert(PatchAction.java:213)
at com.intellij.updater.Patch.lambda$revert$3(Patch.java:379)
at com.intellij.updater.Patch.forEach(Patch.java:396)
at com.intellij.updater.Patch.revert(Patch.java:379)
at com.intellij.updater.Patch.apply(Patch.java:362)
at com.intellij.updater.PatchFileCreator.apply(PatchFileCreator.java:83)
at com.intellij.updater.PatchFileCreator.apply(PatchFileCreator.java:75)
at com.intellij.updater.Runner.doInstall(Runner.java:323)
at com.intellij.updater.Runner.lambda$install$0(Runner.java:290)
at com.intellij.updater.SwingUpdaterUI.lambda$doPerform$2(SwingUpdaterUI.java:194)
at java.lang.Thread.run(Thread.java:745)