Some of the known issues on Forms in EBS

Login Issue: FRM-92101:There was a failure in the forms server during startup. [Document 758661.1] After Upgrading the Forms Tier JDK to the Latest Certified Version of J2SE 5 or 6, Ebusiness Suite Forms Fail to Open With an FRM-92102 Error [Document 973632.1] FRM-40735 Error Received When Trying To Define A Responsibility [Document 1269544.1] R12: "FRM-92050: Failed to connect to Server:/forms/lservlet:-1" Error When Launching Forms After Adding New Language [Document 1062246.1] While Trying To Resolve FRM-92101 On E-Business Suite Release 12 By Recompiling Forms, It Fails With "ldflags: Too many levels of symbolic links" [Document 465926.1] R12: "FRM-92101: There Was a Failure in the Forms Server During Startup" Error After Fresh R12 Installation [Document 429627.1] "FRM-92050: Failed to connect to the server :/forms/lservlet -1" Error When Attempting to Launch Forms with Reverse Proxy [Document 779065.1] R12: "FRM-92050: Failed to connect to the Server: /forms/lservlet: -1" Error After Upgrading JDK [Document 1175400.1] R12: Forms Timeout More Than 2 Hrs Is Not Working After R12 Upgrade [Document 734077.1

Note 1258305.1 Users Receive FRM-92101 oracle.forms.net.ConnectionException Errors When Launching E-Business Suite Forms Responsibility and Function
Note 454427.1 R12: "FRM-92101:There was a failure in the Forms Server during startup" Error When Attempting to Launch Forms
Note 438231.1 FRM-92050 Connecting and "Failed to exec runform f60webmx" Starting Forms Server
Note 1103744.1 R12: "FRM-92101: There Was a Failure in the Forms Server During Startup" Error When Loading Forms
Note 1056333.1 Forms Error With FRM-91126 invalid value timezlrg#dat
Note 744093.1 FRM-92050 With "Connection reset by peer: JVM_recv in socket input stream read" Error When Launching Form On Microsoft Servers
Note 1203773.1 Forms raises FRM-92100 Caused By Java.IllegalStateException:Cannot Open System Clipboard
note 130686.1 How to Generate Form, Library and Menu for Oracle Applications
Note 438652.1 R12: Forms Runtime Diagnostics (FRD), Tracing And Logging For Forms In Oracle Applications
Note 840577.1 Getting FRM-41839 FRM-41092 FRM-40737 FRM-40734 When Using Mouse Scroll on Oracle Applications 12.0.4
Note 550364.1 FRM-40735: Pre-Update Trigger Raised Unhandled Exception ORA-04062
Note 754347.1 FRM-40833: Could not completely load the dynamic user exit libraries
Note 399652.1 Getting FRM-41800 when navigating to any LOV and Focus Lost
Note 1369830.1 R12 Forms Slow performance / Freezes / Hangs for large # Record details using View -> Last -> Record

For troubleshooting you may review the following:

Note 365529.1 Troubleshooting FRM-92XXX Errors in Oracle Applications
Note 311019.1 Troubleshooting FRM-92100 Issues In Oracle Applications 11i
Note 402674.1 Tips and Queries for Troubleshooting Forms Session Timeout Issues
Note 164220.1 Troubleshooting "FRM-92160: Web client version too old" Error in R11i
Note 810084.1 Troubleshooting"Forms CGI error: URL Contains One Or More Restricted Characters" In Apps 11i
Note 136027.1 Troubleshooting Oracle Forms 6i Issues With Oracle Applications 11i
Note 299187.1 11i: How to Troubleshoot Error "FRM-92050 Failed to connect to the server"
Note 164220.1 Troubleshooting "FRM-92160: Web client version too old" Error in R11i