How can i solve the GssParserException problem

[gdsaiful]

Compiler parsing error: Parse error in /opt/codes/productname-test/productname/src/main/webapp/wc/4.0.0/css/admin/admin.css at line 10,759 column 28:
filter : alpha(opacity:0)
^
com.google.common.css.compiler.ast.GssParserException: Parse error in /opt/codes/webcommanderv4-test/WebCommander/src/main/webapp/wc/4.0.0/css/admin/admin.css at line 10,759 column 28:
filter : alpha(opacity:0)
^
at com.google.common.css.compiler.ast.GssParserCC.parse(GssParserCC.java:214)
at com.google.common.css.compiler.ast.GssParserCC.parse(GssParserCC.java:234)
at com.google.common.css.compiler.ast.AbstractGssParser.parseInternal(AbstractGssParser.java:56)
at com.google.common.css.compiler.ast.GssParser.parse(GssParser.java:46)
at com.google.common.css.compiler.ast.GssParser.parse(GssParser.java:42)
at com.google.common.css.compiler.commandline.DefaultCommandLineCompiler.parseAndPrint(DefaultCommandLineCompiler.java:126)
at com.google.common.css.compiler.commandline.DefaultCommandLineCompiler.compile(DefaultCommandLineCompiler.java:110)
at com.google.common.css.compiler.commandline.DefaultCommandLineCompiler.execute(DefaultCommandLineCompiler.java:156)
at com.google.common.css.compiler.commandline.ClosureCommandLineCompiler.executeJob(ClosureCommandLineCompiler.java:374)
at com.google.common.css.compiler.commandline.ClosureCommandLineCompiler.main(ClosureCommandLineCompiler.java:440)
Caused by: com.google.common.css.compiler.ast.ParseException: Encountered " "0 "" at line 10759, column 28.